Fulbright in Portugal

Steve Doig in Lisbon August-December 2010

Lisbon skyline

Counting heads

It’s not all porto and pastéis de nata for me here in Portugal. I spent yesterday doing journalism.

I was contacted a couple of days earlier by Curt Westergard, whose Airphotoslive.com company uses cameras on tethered balloons to produce high-resolution aerial photos. He had been hired by CBS News to get images of the crowd that gathered Saturday for the Glenn Beck “Restoring Honor” Tea Party rally at the Lincoln Memorial in Washington. CBS also wanted a credible estimate of the size of the crowd. That’s where I came in.

I started doing crowd estimates back in my Miami Herald days, for local events such as a visit by Pope John Paul II or the annual Calle Ocho street festival. After the 2008 presidential election, I wrote a piece about crowd counting for MSNBC.com, and that led to news media requests for an estimate of the crowd for President Obama’s inauguration. I used a satellite image taken over the National Mall on January 20, 2009, to estimate the crowd there at about 800,000.

Crowd counting, particularly of political events, always is controversial. The organizers of the event inevitably hype their crowd estimate — often grossly — to demonstrate the popularity of their cause, and opponents inevitably underestimate to fit their own agenda. Because of the wild pre-inauguration predictions of how many would attend in person — up to 5 million! — my reality-based estimate was ignored by many left-wing commentators and embraced by those on the right.

Naturally, I expected more of the same about my Beck rally estimate. To calculate it, I used Airphotoslive.com’s very striking images (MUCH larger than the thumbnail posted here)

Airphotoslive.com shot for CBS News

to make density estimates across different zones of the crowd; a variety of ground-level images from news photographers and attendees who posted their photos on Flickr; and Google Earth to measure the square footage of the different zones. Yes, I included the crowd areas under the trees; the full-size Airphotolive images were detailed enough to discern the edges of the crowd even there.

My estimate is that about 80,000 people were at the rally. Ryan Shuler, an Airphotoslive image analyst, used the same images and a different grid-density method to produce an estimate of 87,000. Considering the error margins around our separately-calculated estimates, they are statistically identical. CBS went with the 87,000 figure, which I certainly can accept.

Now the fun begins in the blogosphere. NBC News, the New York Times, and other large media outlets that didn’t attempt a scientific estimate uncritically accepted Beck’s claim of “300,000 to 500,000″. (At least Rep. Michelle Bachmann’s laughable claim of 1 million isn’t being treated seriously.)

The CBS News estimate immediately was vilified by conservative bloggers, and often rabidly-virulent comments from readers are being posted on news stories that mention the CBS estimate. I won’t post more links, but you can find plenty by Googling “beck rally attendance” and similar search terms.

The frothing underscores the problem with hyped predictions of crowd size. Organizers and supporters are forced to insist loudly that the actual crowd met or exceeded their expectations, for fear that the realistic estimate will be painted as a disappointment. The time-honored way to dismiss scientific estimates that don’t reflect the pre-event hype is to claim political bias on the part of those doing the estimate. I am amused to see that those who embraced my Obama inauguration estimate as soberly realistic are now attacking the Beck rally estimate, produced using exactly the same methods, as deliberately biased.

I expect that kind of behavior from partisans on both sides. I am disappointed, though, by the many responsible news organizations that failed to produce their own independent estimates and instead reported only ungrounded hype. Their readers and viewers deserve better journalism than that.

[DOIG afternote: I welcome reasoned comment and questions. Don't bother sending ideological rants from any direction; I trash those. Also, it may take a while for your comment to be read and approved. I'm in Portugal five hours ahead of DC, also the flood of hits on the site has slowed it way down.]

[UPDATE: Those interested in this topic might also read this followup note.]

75 Responses to “Counting heads”

  1. August 29th, 2010 at 9:15 am

    World Wide News Flash says:

    Counting heads…

    I found your entry interesting so I’ve added a Trackback to it on my weblog :)

  2. August 29th, 2010 at 12:51 pm

    Tom Allen says:

    Nice job, Steve. Through all the years and all the rallies going back to MLK in ’63 and including the Vietnam moratoriums I’ve always been skeptical about the purported size of these gatherings. Given the available space extending from the Lincoln Memorial to the Capitol I don’t see how more than about 90,000 people can wedge in there.

  3. August 29th, 2010 at 1:13 pm

    Scott Klein says:

    The 02-03 protests against the Iraq War yielded similar complaints about undercounts, from the other side. None quite so bad as the unscientific NPR guesstimate of the October 2002 march, which was hastily retracted.


    I will say that when you’re in the middle of one of these things and there are people as far as you can see in all directions, it seems like a bazillion people must be there.

  4. August 29th, 2010 at 4:40 pm

    Christia gibbons says:

    Thanks for the lesson I’m passing on to my JMC301 students. Not only will be a lesson in what can be done, but what should be done.

  5. August 29th, 2010 at 9:42 pm

    Jeff says:

    “Given the available space extending from the Lincoln Memorial to the Capitol I don’t see how more than about 90,000 people can wedge in there.”

    You must mean 17th St. as the aerial photos of the Beck event clearly show a crowd from the Lincoln Memorial to 17th St./WW2 Memorial and a sprinkling up towards the Wash. Monument. The area from the Lincoln Memorial to the Capital would be the crowd for the Obama Inaugural where Steve gave an estimate of 800,000.

    [DOIG COMMENT: "Yes, Jeff is right. The Lincoln>WW2 area where the Beck crowd gathered could hold about 125,000 if everyone was in an arm's reach of those around them."]

    Anyway, nice work Steve. Glad someone ask and paid for a real count.

  6. August 30th, 2010 at 3:04 am

    TMLutas says:

    When you say “I used Airphotoslive.com’s very striking images (MUCH larger than the thumbnail posted here)” I hope you meant that the area covered was much larger than is shown in the thumbnail. The alternate construction is that the area covered is the same but the resolution of the area is much larger. Usually it’s the second interpretation that is the case when you thumbnail an image. You shrink it without cropping it.

    Based on AP photography, there are large sections of the crowd that you’ve outright missed if the second interpretation is true. That’s not necessarily your fault if you didn’t get photos covering the entire crowd but it *would* be helpful if you would clarify which interpretation is correct. If you’ve been led astray by receiving incomplete crowd photos, you really should act to protect your professional reputation.

  7. August 30th, 2010 at 5:32 am

    Steve Doig says:

    Of course. The ballon was tethered south of the Reflecting Pool several hundred feet east of the Lincoln Memorial. The Airphotoslive crew got images taken both to the west and to the east. The entire crowd area and surrounding grassy areas and lakes was visible. The AP shot from the Washington Monument is a fine news image, but taken too far back at too oblique an angle to be useful for crowd counting. The images are large (16Mb). I will post links to the images once Airphotoslive releases them.

  8. August 30th, 2010 at 4:35 pm

    Jay Rosen says:

    Where are the links to the Obama supporters disputing the 800,000?
    [DOIG reply: Jay, I dimly recall from 20 months ago there were some people who explicitly wrote the 800k estimate was too low. But I don't keep a record of the reaction to my every public utterance. I do recall that many commentators instead just went with the 1.8 million estimate published by the Post. That's why in this post I wrote my Obama estimate was "ignored" -- I didn't say it was attacked as being tainted by ideology.]

  9. August 30th, 2010 at 4:41 pm

    Norm says:

    16 Mb is large for a consumer grade camera but here is a link to a large photo of Obama’s inaguration.


    59,783 X 24,658 pixels or 1,474 megapixels.

    [DOIG reply: Yes, that's a fabulous image! Making it required hundreds of shots.]

  10. August 30th, 2010 at 4:53 pm

    Zach D. says:

    Thank you for this professional and edifying explanation of your crowd estimate. I was there and would guess at least 100,000. The crowds beyond the Washington Monument were sparse because that was out of earshot of the speaker system. Even the sound at the WM was weak and with too much echo. Another factor that changes density is the use of large TV monitors throughout the space. People are willing to crowd in very tight to view the TV screens. People who only are within earshot of the speaker system are content to spread out a blanket and take up more room per person. Also, pedestrian access was not manipulated with fencing until you got near the Reflecting Pool. During the Inauguration you could not walk from anywhere north of Penn Ave to access the Mall unless you used the 3rd Street tunnel or 14th Street by the Washington Monument; so those were two artificial chokepoints, not normally seen for gatherings on the National Mall. Indeed the TV monitor by the Washington Monument had the most dense crowd of the day. I was lucky and was closer to the 9th Street screen. The use of WMATA’s subway ridership statistics is interesting since you can compare them to any other Saturday and to other large gatherings in the city. The weather also helped, it was seasonable and almost cool in comparison to the last many weeks in D.C.

  11. August 30th, 2010 at 5:00 pm

    John H says:

    Fascinating – many thanks for the insight of how you did the count.

    And I agree – the real disappointment is in the media not doing more fact checking. Kudos to CBS.

    Now I wonder how long before the “Beck crowd” find some willing statistician (likely with a dubious background) to back their claims? It seems to me like their are many “experts for hire” and this would seem like a way to try and muddy the waters (reminds me of estimating the oil release and slick size).

    Again – many thanks for taking the time to explain this in a rational manner. I must admit I was skeptical of how low your number was before investigating more.

    Politicians should just stick with made up numbers “bazillions” and “gazillions” should suit their agendas just fine…

  12. August 30th, 2010 at 5:08 pm

    steevithak says:

    Interesting stuff! Has anyone developed image processing techniques which can estimate crowd numbers from the photos algorithmically? Or are all the estimates done manually by humans at this point?

    [DOIG reply: I'm sure there's software like that being used by the NSA, CIA, NRO and other agencies that have access to high-quality aerial/satellite imagery. I certainly don't -- alas!]

  13. August 30th, 2010 at 5:10 pm

    Gary Polson says:

    If you go to scholar.google.com and enter the phrase: aerial crowd estimates

    you will find several technical articles on this subject. We have followed it in the past as it pertains to recreational events and boating activity levels.

  14. August 30th, 2010 at 5:11 pm

    Frank Stein says:

    Is Body Mass taken into consideration when estimating or is it truly a head count? I’m guessing that the typical Tea Party supporter in 2010 takes up more room physically than the typical civil rights or anti-war protester from the 60′s.

    [DOIG reply: Sadly, based on the evolution of my own body since the '60s, I suspect that observation is true of most Americans no matter who or what they support!]

  15. August 30th, 2010 at 5:21 pm

    Daithi says:

    Why not just post some of the actual Airphoto pictures? That way people could estimate for themselves. We could count people in a small area then extrapolate that out for approximately the whole area covered. We really don’t need an accurate count, but just enough to make out whose side is closer to the truth. BTW I believe Beck’s estimate was based on bus counts registered to bring people to the event — i.e. it was not exactly the unscientific or uncritical estimate this article made it out to be).

    [DOIG reply: I don't own the rights to the Airphotoslive images; I was simply asked to use the images to make the estimate. I believe CBS News, which hired Airphotoslive to take the images and make the estimates, controls the image rights. I hope the images are made public.]

  16. August 30th, 2010 at 5:21 pm

    George says:

    Why not post similar pictures of the Beck rally, million man march, Obama’s inaug and MLK rally and let us decide for ourselves how they rate. Maybe that makes too much sense.

    [DOIG reply: Those images are out there on the net to be found. Feel free to do what you suggest.]

  17. August 30th, 2010 at 5:25 pm

    zen says:

    We went through a similar issue in boston last spring. The tea party express came through and scheduled a rally on the boston common. Weather was good, turnout was poor. Professional estimates were in the 2000. They permitted for 10,000. Supporters accused the ‘liberal media’ of intentionally downplaying the turnout, but turnout was so sparse that even a non-professional could manually count the numbers from the aerial photos.

    You’re never going to convince the rabid tea party supporters that there was anything less than 500,000.

    I guess the only way we’ll really figure out just how many people really support this ‘movement’ is by the next election results.

  18. August 30th, 2010 at 5:27 pm

    Muzhik says:

    Greetings! I know Mr. Beck was getting his information from reports of the 1963 MLK rally, which indicated about 200,000 in that area along the reflecting pool. Obviously, if reports at the time placed that estimate at 200,000 and if a rally today “fills” the same space, then today’s rally must also be 200,000.

    Again, crowd density must be considered. By “arm’s reach” do you mean if I stand with one arm horizontal and spin in a circle, I can touch each person around me?

    It seems the MLK rally is the benchmark for all other rallies, rather like how rock bands today compare their crowd attendance to what the Beatles drew when they played in that particular venue. Out of curiosity, have you tried going over historical photos of the MLK rally and tried to develop estimates of that crowd, to give us some measure of comparison? If, by your study, you determine that the MLK rally only drew, say 125,000 instead of 200,000, that might give us better comparisons, esp. in future rallies.

    (I would LOVE to see someone do a study where they took exactly 1,000 people, put them in the Mall in different places and different densities, took aerial photos, and tried to have different methodologies calculate the number of people were in that place!)

    [DOIG reply: I, too, would love to see such studies. I'll add that I'm skeptical of crowd estimates done in earlier decades without the benefit of overhead aerial imagery. For instance, the LBJ inauguration estimate of 1.2 - 1.5 million almost certainly is what is known in the crowd-counting business as a Wild Ass Guess.]

  19. August 30th, 2010 at 5:27 pm

    MjM says:

    Steve, will you reveal the specifics of your methodology? 5s.f., 10s.f.?

    [DOIG reply: I was hired -- at a VERY modest fee -- to make the estimate; CBS News owns the rights to the images and my detailed report to them on my estimate methodology. So, no, I can't be very specific. I do refer to my method in general terms in this posting. I will say that I used 10 sf per person for the tight crowd lining both sides of the pool, and larger values for different crowd regions along the flanks. I'll add that 5 sf would be mosh-pit scary.]

  20. August 30th, 2010 at 5:39 pm

    Karen Heybey says:

    This is very interesting and I am so glad that you saw fit to share. I was one of the attendees and I am quite curious about an accurate count. Someone commented that it must seem like a bazillion people when you are in the crowd. Quite right! I would say that if Airphotoslive people do not have images from 17th St. to the Washington Monument, then they are definitely missing part of the count.

    [DOIG reply: The Airphotoslive images include very good shots to the east, toward the Washington Monument, and those were included in the estimate.]

    For a large part of the event, I was on the north side of the Reflecting Pool back over the hill and seated near the pond. People were not standing shoulder to shoulder, but the area was full. People were also in constant motion along those foot paths. Around 12:30 pm my companions and I moved to the area between 17th St. and the Washington Monument. At that time the crowd was dense in front of us and started to dissipate dramatically behind us. I pivoted in place to take a photo to the north because there are recognizable buildings that serve as a landmark for figuring how far back from 17th St. the crowd was densely populated.

    Looking forward to hearing more and seeing the photos.

  21. August 30th, 2010 at 5:48 pm

    Newell Franks says:

    I attended the rally. I have been in Michigan Stadium with a crowd of 108,000 people. Just for fun I did the math mapping Michigan stadium against the area occupied by the crowd I was in. Much of the crowd density at the Beck Rally was lower than Michigan Stadium. Some of the crowd density was higher. Along the pathways paralleling the reflecting pool on both sides under the trees people were crowded standing shoulder to shoulder. In other areas like the open field areas people were sitting in chairs or standing. The areas under the trees on the North side of the reflecting pool were also full of people. In the aerial shot from the Washington monument side you can see them spilling out into the field in front of the Vietnam war memorial. The crowd I was a part of made the crowd at Michigan stadium look like a high school football game.

  22. August 30th, 2010 at 5:49 pm

    Ken Gettys says:

    I didn’t see it noted that during any nice, sunny summer day, that there are 1,000s of people already visiting these famous national monuments. And I would also think that for any major event, there would be people that turn out just to be there (perhaps just to people watch) and not necessarily a supporter of the event’s theme!

  23. August 30th, 2010 at 5:51 pm

    MattDC says:

    Very interesting analysis. As a long-time resident, I’ve never found the crowd estimates to correspond to my personal experience. From the Obama inauguration, to the “Million” Man March to John Paul II’s Mass on the Mall, I’ve often wondered whether anyone really tried to go about it scientifically. Most journalists seem to have given up, and make things worse by using self-serving quotes from participants or anecdotal supporting evidence, like backups at the Metro. (Judging from the rush hour backup on Friday alone, caused by confused tourists at farecard machines, I’d estimate about 10 million prople). Your estimating approach seems sound. And my own experience, both on the Mall and at several outdoor mass concerts over the years, suggests that 100,000 people might be a generous estimate. Rep. Bachmann was right about one thing: there were witnesses present.

  24. August 30th, 2010 at 5:54 pm

    Joel says:

    I found your article interesting in regards to accuracy on crowd counting, but in the interest of journalism why do you refer to the event as a Tea Party rally? From what I can gather there is no connection between this event and the Tea Party per se and to call it such is bad journalism just like reporting bad numbers because it interjects a philosophical slant on the story.

    Other than that, great article!

  25. August 30th, 2010 at 6:03 pm

    Kyle fer says:

    Thanks for your estimation. I was there…..Not for support, but rather to bring a group down on a bus. Anyway, largest crowd I have ever been to. I have went to an ohio state football game before (this was compared to 80,000) and the comparison was comical. Anyway, I think u r wrong, as is most other people. Out of curiosity, what party do you belong to? Just asking because an article was written indicating the estimation is simply made depending on your political beleif…..makes sense and I see you wrote for MSNBC…..u friends with Olberman. :) Anyway, I bet your count is at least 100 people short because u did not mention that you considered the people in the porta pots and there was at least a hundred of em.

    [DOIG reply: Good one! Okay, my estimate is now 80,100.]

  26. August 30th, 2010 at 6:04 pm

    Sandhog says:

    Very good article. One observation with regard to the last statement: “Their readers and viewers deserve better journalism than that.” Keep in mind that most readers/viewers are lemmings who don’t think for themselves, so the quality of the media or journalism really isn’t going to matter.

  27. August 30th, 2010 at 6:11 pm

    maclogo says:

    “I guess the only way we’ll really figure out just how many people really support this ‘movement’ is by the next election results.”

    I’m good with that.

  28. August 30th, 2010 at 6:17 pm

    Gerald says:

    Oh, thanks to the wonders of modern technology, it’s fairly easy to check your figure of 80,000. Using these aerial photos
    http://www.leftcoastrebel.com/2010/08/photos-aerial-pictures-of-glenn-beck.html and then using the pictures below that one you can actually count heads to get the density of the crowd. Based on that, just between the tree lines and the reflecting pool, the estimate would be over 150,000 people, so maybe you should recheck your numbers.

    [DOIG reply: Those images taken from the Washington Monument are striking, but are too far away and too oblique to work for estimating density.]

  29. August 30th, 2010 at 6:32 pm

    Red says:


    Speaking of oblique angles, the sun would have had to have been pretty low in the sky to have cast a shadow from the Washington Monument that far down the reflecting pool.

    The rally was held from 10:00 AM to 1:00 PM. A picture taken at noon would have cast almost no shadow at all of the Washington Monument into the reflecting pool.

    At what time of day do think this picture was taken?

    [DOIG reply: I know the images were taken at noon. That isn't a shadow of the Washington Monument in the Reflecting Pool; it's coloration or debris on the bottom.]

  30. August 30th, 2010 at 7:58 pm

    Jeff Green says:

    Some years ago some friends reported back from an anti-war march in which he said 100,000 split off and went marching off on their own. He included a description of the route down Pennsylvania Avenue and said people were shoulder-to-shoulder for ten blocks… So, I decided to do a little research, found out how wide PA avenue is, gave each person 2.5 feet on the ground and came up with 35,000…. the exact same number as an unofficial police estimate I did not know about until some days later. Suffice to say that this friend is no longer as I was surely part of those who love war in order to diminish his experience.

    Look, I’ve marched against enough wars and I know what the head-counting thing is all about. But to me it’s better to be honest about these things for if we cannot trust you on something as simple as a head count how can we trust your decisions on policy?

  31. August 30th, 2010 at 8:11 pm

    Door King says:

    I used to report, and when there were hot meetings, I’d count all the seats available before the meeting, and work out a grid. The day after the paper came out, about as many people as were at the meeting would file in to the publisher’s office to seek my dismissal for over-estimating or under-estimating the crowd. Thanks for a bit of rationality.

    [DOIG reply: I know exactly what you mean. During my reporting days, I also would count seats, or look for the fire marshall sign declaring maximum capacity, and then estimate the percentage filled. And inevitably, I'd get complaints about my count being way too low or too high.]

  32. August 30th, 2010 at 8:24 pm

    T.J. says:

    Why does everyone have to hate on everyone else? This rally was about coming together and standing up for morality. Unless you are totally against honesty, integrity, or honor, you should applaud this gathering. It is pathetic there are people who hate someone else soo much they have to make fun of a crowd estimate. I say there was 20,000 people there. Everyone make fun of me! How rediculous.

  33. August 30th, 2010 at 8:27 pm

    rastadog says:

    Steve, I have noticed that organizers of tea party events have a way of organizing space to create illusions of larger crowds, at much smaller local rallies. They make large arcs of empty space around the stage (using elderly people in their lawn chairs for the front row border. It really does make the crowd go back farther, and thus appear like a larger group. Thanks for your work.

    [DOIG reply: Well, strategies for making crowds appear larger aren't confined to TP organizers. An example is the use of low-angle images that make a crowd seem an unbroken sea of people. That's why good overhead images are so important to estimating a large crowd.]

  34. August 30th, 2010 at 8:32 pm

    Alvin says:

    Did anyone take into consideration the attendees under the trees? A comment was made before the event that arial photos could not discern people on the walking paths. Photos show people packed from the fenceline at the pool outwards and meeting the groups in the side clearings. Your thoughts?

    [DOIG reply: Yes, the crowd went well back into the trees. And yes, I included that area in my calculations.]

  35. August 30th, 2010 at 8:33 pm

    Michael Pelletier says:

    So are you saying that this scattered set of crowds from the Capitol to the Monument:


    … was 800,000 people, but the Beck rally had 1/10th of this attendance? Just eyeballing it, that doesn’t seem correct. Or is there another more populous inauguration photo you’re referring to?

    I’ve also been to Michigan Stadium as well, and flipping between two Google Maps at roughly the same scale (same zoom level), the entire stadium with its football field and 112,118 seats could fit snugly between the reflecting pool and Constitution Avenue, and between Henry Bacon Drive and Constitution Gardens Pond with room to spare.

  36. August 30th, 2010 at 8:42 pm

    David says:

    I am a huge Glenn Beck fan and wanted there to be more people. I make detailed statistical maps for a living and do crowd estimates as a hobby. 87,000 plus or minus 9,000 is exactly right by my methods.

    From the photos of the Million Man March, there were at least 850,000 people there. Assuming the mass of humanity extended beyond what I saw photos of, 1 million attendees would easily have been achievable.

  37. August 30th, 2010 at 8:50 pm

    Tim Dolan (AKA Longwatcher) says:

    I am a retired USAF Imagery Analyst and have had the opportunity in the past to do crowd estimates. My rough eyeball call of the crowd in the two pictures I have seen claimed to be from airphotoslive.com was no more then 165,000 attended the rally based on the area covered. And then actually looking at the image, the density of people was considerably lower in certain areas. So my WAG without doing detailed analysis would estimate in the ~95,000 range, well within error of margin for the 80-87,000 range.

    For trivia, when I have done them in the past, I used a defined grid system and then determine density levels for each grid. each density level will have a value. add up all the values and you have an crowd estimate. Much, much faster then counting heads and about as accurate based on human nature.

    And a big factor a lot of people don’t realize is how much space on the ground an average person takes up in an average crowd. It has been awhile but I seem to remember something like 4.5 Sq Ft in a dense crowd, 6-8 Sq Ft in a medium crowd.

    Anyway, glad someone was trying to get an accurate estimate

  38. August 30th, 2010 at 8:58 pm

    dennis says:

    Thanks for your work, including the attitude which seems just right … and thanks to the participants in this discussion being civil and reasonable (screened I’m sure). This is such an important issue — not crowd counts per se, but the ability to still come to some common ground on OBJECTIVE REALITY and mutually trusted methods for getting at the truth. It really scares me to see the extent to which our society behaves like a crowd at a game that can’t get their eyes to see (or brain to admit) the foul they witnessed if it was committed by their team — and won’t believe the ref is trying to be objective, unless the call goes their way. It’s more than “partisanship” we are seeing bust out all over; it’s a kind of mental or spiritual illness that is going to do a lot of damage to us all if we don’t figure out how to get a handle on it. If people want to call something “fascist” or reminiscent of Hitler or Stalin, then put those names on the attempt to force a reality on others that you desperately want to believe but can’t prove by rational means. And of course, rational and objective are concepts that many of us simply do not, or do not want, to understand or appreciate. Very scary. To find and propound the truth requires a discipline of honesty and humility within one’s self; it is a calling, like that for a life of faith, but it’s one we all need to answer.

  39. August 30th, 2010 at 9:06 pm

    nmb says:

    One problem with an exercise such as this is that there is no accepted standard by which to compare it to (i.e. is there an accepted attendance count for some other event at the National Mall to compare this to visually, as at least a gut check to see if your count is in the ballpark?

    Speaking of ballpark, I would suggest as an exercise superimposing over the National Mall photo, a scaled photo of, say, a sports stadium with some known capacity of people. I know the densities of people would be different in each case (crowds loosely filling a field versus compact, ordered rows of seats), but at least one could see visually what 80,000 people in the National Mall looks like compared to 80,000 people at, say, Nebraska’s Memorial Stadium (81,067 capacity) (http://en.wikipedia.org/wiki/Memorial_Stadium,_Lincoln).

  40. August 30th, 2010 at 9:24 pm

    dendroica says:

    On shadows: Since DC is about 37 north, and the sun is currently about 5 north, and 12PM is almost exactly an hour before solar noon (daylight savings time…) then the angle of any shadow would have to be at the very least, 33 or 34 degrees. In which case you’d have a Washington’s Monument shadow about half its height, which if memory serves would make it nearly 280 feet long. Even if the “shadow” isn’t the WM, it just shows that people need to know their basic math, physics and geometry in order to make general assessments.

  41. August 30th, 2010 at 9:39 pm

    Gerald says:

    Since crowd estimates are your area of expertise, I will counter with this very conservative estimate of 215,000 by Charlie Martin. http://pajamasmedia.com/blog/glenn-beck-rally-how-big-was-the-crowd/2/
    He lays out the methodology he used to get his number. Used a density of 1.1 person per square meter which seems to be supported by the photos. Maybe you could compare your methodology with his. Just based on the number of buses (1100) seems your number is really low.

    [DOIG reply: 1.1 persons per sq meter is pretty close to 10 sq ft per person, which is the density I used along the pool. Outside of that area, the crowd was thinner.]

  42. August 30th, 2010 at 9:54 pm

    Peg says:

    There is no way any company who does this for a living and has conservative clients would ever risk their reputation by undercutting the numbers, it makes no sense. Beyond that, you need to take into consideration that Metro gave an increased ridership of 200,000 people over most days and other Saturdays. Take that number and divide by 2 for inbound and outbound and consider there were two major sporting events and other events and you end up back with the 90-100k number.

  43. August 30th, 2010 at 10:05 pm

    mickeymorris1234 says:

    I really want to know how you came up with your numbers. The area that Beck supporters filled (not including the scatter at the back) is roughly 1,700,000 square feet. (Based on a Google Maps Shot and photos of the rally showing the more dense areas of the population.) Based on these photo’s taken on the ground (http://www.glennbeck.com/content/articles/article/198/44954/)you can figure that every person at the rally (based on multiple pictures and yes I figured each photo and took the average) had approx. 4.4 feet to themselves (towards the back of the pack it was aprox. 5.6 and the front was aprox 3.2 feet (keep in mind the average chair takes up 19 sq inch.) ) I get the number of 386,363 people. Rounding down to aprox 386,000 people in the dense area. We could then assume a margin of +- 10,000 seeing as we did not count all the people.

    Next we can look at a real life example. Dodger Stadium can hold 56,000 people. It’s seating area is aprox. 331,000 square feet. Which means everyone gets about 5.9 sq feet to themselves (including isles and rows) Taking those numbers and with each person getting 5.9 feet to themselves you still get 288,000 people there. Yes smaller than the 500,000+ people reports (I never believed that) however saying anything less than 250,000 people there is an absolute joke and you should know better than that.

    Check my numbers, I told you where I got my pictures from. (And if you are wondering yes I took out the reflecting pool when I calculated sq footage)

    And just for laughs and giggles, I used a computer program called Vivien and punched in the area occupied by those at the 8/28 rally and told it to calculate how many people were there. (Remember computers don’t lie)

    Guess what number it came up with – 384,634. Just so you know what I punched in – (since it is an event planning software is doesn’t calculate people it calculates chairs) Theater chairs with the arms with 8 inches between each chair and 1 ft 6 in. in front of each chair. Using the same sq. footage I used above the magical number it came up with TA DA! 385,000 people! (Rounding up)

    [DOIG reply: An average density of 4.4 sq ft per person across this entire crowd is WAY too tight. That would mean everyone is standing and pressed together front to back. See all the green grass in the thumbnail above?]

  44. August 30th, 2010 at 10:10 pm

    Prantha says:

    Let’s compare the photo you used to the photos of other events:

    What two hundred thousand looked like when MLK actually spoke: http://politic365.com/files/2010/08/View_of_Crowd_at_1963_March_on_Washington-e1282849498904.jpg

    Obama on November 4, 2008: http://www2.ljworld.com/photos/2008/nov/04/158534/ and http://www.grandforksherald.com/event/image/id/27330/

    This hi rez image is what a half million looked like a few hours before Inauguration in January 2009.

    What a million looked like that day in January 2009: http://cache.boston.com/universal/site_graphics/blogs/bigpicture/44_01_21/4405_17676915.jpg and http://news.cnet.com/i/bto/20090120/inauguration_1_crop.jpg

    Typical big rock concerts with large crowds: http://www.noiseaddicts.com/2009/08/concerts-with-record-attendance/

    Just a simple visual, non-mathematical comparison shows he got a crowd of around 80K.

  45. August 30th, 2010 at 10:11 pm

    Jay says:


    The estimate you cite is deeply flawed because he uses uniform crowd density estimates across the whole depth of the crowd. It’s fairly apparent even to the naked eye that the areas away from the reflecting pool are at a far less than 10 sf per person. There is quite a lot of grass visible, as well as people sitting down and even chairs and blankets.

    Density changes the figure dramatically, and only a small portion of the area discussed in that blog was actually close to 10 sf a person.

    Not to mention, somehow at the end he decides a possible estimate would be doubling the 75% number, which really makes little sense. There’s no doubt the vast majority of the crowd was covered in the picture he used… arbitrarily saying the same amount of people may be elsewhere is not really a good method for estimating.

  46. August 30th, 2010 at 10:26 pm

    ChristaJeanne says:

    Not to be persnickety, but it wasn’t a Tea Party rally as you say – that’s a gross factual error, as we called them in journalism school. ;) The media keeps attaching the rally to the oft-maligned, eyerolls-from-the-left-inducing Tea Party movement, but it didn’t have anything to do with the Tea Party or its platforms. Sure, there’s overlap in the demographics attending each, but that doesn’t mean one is the other. Please correct the error.

    As for your numbers, I was in attendance, and Beck told the crowd that the area around the reflecting pool plus the lawn on the side toward the WWI memorial held 550,000, not to mention the folks around and beyond the WWII memorial and the Vietnam memorial. Was he that off?

    [DOIG reply: Okay, I regret the casual use of "Tea Party" for an event organized and headlined by those most identified as TP leaders, and attended by tens of thousands of people who consider themselves aligned with the TP. And yes, Beck was off.]

  47. August 30th, 2010 at 10:57 pm

    reg man says:

    I also looked at available aerial photos of both this event and the Million Man March. By my estimates, the MMM took up an area of approx 750 ft X 4000 ft (area between the capitol and the Washington Monument including areas under the trees) plus about 1/4 of the area around the Washington Monument. This is about 3,800,000 square feet. The Beck rally took up an area 2000 X 600 ft (visible area up to the Washington Monument NOT including areas under the trees) or 1,200,000 square feet, about 1/3 the area of the MMM. If the crouds at the MMM were officially 837,000 people, the Beck croud must be at least 250,000. Either that or the original estimates of 400,000 for the MMM were more correct.

    [DOIG reply: I believe the Park Service's estimate of 400k for the MMM is a good one. And just the name "Million Man March" makes my point about the problem of pre-event predictions. A gathering of 400k is fantastic, but by using a catchy, alliterative title, the organizers set themselves up for a "disappointing" turnout.]

  48. August 30th, 2010 at 10:57 pm

    Dennis F says:

    Based on the airial photos I have seen, 80-90,000 would be a reasonable estimate. The total area that is filled with people looks to be about 1.8 million square ft. The average crowd density is not much greater than about 1 person per 20 sq ft, so 90,000 is about what you might expect for a crowd size.

    Of course, you could always say that people were squeezed in to a density of 1 person per 5 square feet, and that would give you a crowd of about 360,000. The problem is that in order to get that kind of crowd density, people have to be spaced at about 27″ center to center, both horizontally and vertically.

    That is about the same crowd density as one would find at Fedex Field on a sold-out Redskins game. The problem is that there would be no isles around the reflecting pool as there are in Fedex Field. Imagine trying to walk around in that kind of crowd!

    Any estimate much above 100,000 is unrealistic, to say the least.

  49. August 30th, 2010 at 11:29 pm

    GregInIowa says:

    Your methodology is entirely inaccurate. We were sitting under the trees in the only spot we could find that would take a blanket, 45 minutes before the rally began.

    The entire area between the trees and the reflecting pool and at least 35 feet up to the pathway in the trees (which was only a few [3-4] feet across and not open, at that) was entirely standing shoulder to shoulder – NOT even remotely 10 sq ft per person.

    We had a 5×6 foot blanket and at no time stood more than 1.5 feet outside of the blanket. Kids, and sometimes adults, sat on the blanket. There were 12 of us – no babies. Even considering a 2 foot border outside of the blanket, which was not consistantly even possible to use, that would come to just over 5.09 sq feet per person and we were in the back, lower density part of the under the tree section way away from the main crowd that were shoulder to shoulder. That is half of what you allocated for the area besides the reflecting pool, which was at least twice the density.

    Yes, it was kind of mosh pit density in places near the water and back to the trees themselves (NOT the branches, the trunks, but without pushing jumping and screaming fan types, so it was doable. Belive me, it would have been impossible to do 10sq feet per person, that’s 10 people in a 10×10 area. More people would have gotten into the area between. Demand was that high.

    We all sat at times in the same area on the blanket too, all eleven of us – in that area, meaning that your methodology for the “low” density areas is inaccurate too…very inaccurate.

    I have done some simple in house measurements here. Two people, including one of larger build, standing close, but not touching, can fit, with two inches between them on the sides and more than that in the back and front in a 4’2″ x 2′ space, which is comfortably close. Two smaller people, or children, would use less. That’s 8.33 sq feet for TWO people. If people are closer, like in a pressing.sometimes touching, it would be less.

    That means that if these rates were used (4.2sq feet per person), which are certainly applicable to the area near the reflecting pool, (if not tighter in some places) you would end up with 238 people per thousand sq feet instead of your 100 people per thousand sq feet. Big difference.

    The reflecting pool itself is 2029 feet long and 167 feet wide. The area between the tree trunks (the tree centers) on the north side and the reflecting pool border (which was fenced off) measures to be about 55 feet (by my Google maps sat photo estimation), but lets say, 50 feet to be non disputational. There arent even big trees down by the Lincoln memorial where things were most dense, but lets set that aside, along with the fact that the area long the reflecting pool where crowds were pressed extended much longer than the reflecting pool itself.

    The area just along the north side of the refecting pool to the tree trunks would give us an area based on a 2029 foot reflecting pool and a 50 foot width of would give you over 24,000 just along the front strip of the north side of the reflecting pool. (Your calculation rate would yield There were easly this many as well on the similar strip on the south side and probably a similar density (SRO). That would give 48,000 just on the front areas to the tree trunks, not including the front near the Lincoln or the rear behind the pool or including the vast majority that were on the sides behind the front line of tree trunks which could not get to those slim defined areas for the press of people.

    Off hand, it looks to me that there were at least 150,000 on the north side alone and that you are off by a magnitude of more than 2x in your total and that being somewhere on the higher end between 200,000 and 300,000 that were present, maybe more. There were, from the photos I have seen, at least three times as many attendees behind the tree trunks as were in front of them. Add the front and rear and it’s 200,000+ easy. Bachman’s estimate seems impossible, although it would seem such being in the midst of the press. I would also include your figure in the impossible category. But 300K is not impossible.

    I do not think you are intentionally calculating wrong, just have allowed for a way too generous space per person rate in your methodology.

    One thing is for sure, there is no way to get a real count…unfortunately, especially with trees in the way. (Which concealed an amazing mass of people – it truly surprised me as to the density up front and under the trees.)

  50. August 30th, 2010 at 11:45 pm

    ian marquise says:

    the washingtom metro announced that 510k riders that day. This is 180k more than the next largest crowd in the month of august. I appreciate your scientific approach; however, it can’t match pure data. considering this fact and all the buses and cars that drove in that day you leave about 200k people unaccounted for.

    DOIG reply: Presumably many in that 180k surplus are riders who took the Metro in for the rally and then took it back out after the rally was over. You can’t count the same people twice.]

  51. August 31st, 2010 at 12:20 am

    Lois says:

    I would really like to see the photos that were taken at about 12:30 and not the ones taken at 9:30!!!!!the line for the metros were 1 hour long. Metro said they had NEVER seen anything like it. lots of people got there late you could see the crowd thickening at the Washington monument lawn all threw the event. there was a plane flying over at the end of the rally those are the ones that we will probably never see.

    [DOIG reply: The images I used for the estimate were taken right at noon. I don't know why you think 9:30.]

  52. August 31st, 2010 at 12:31 am

    Lois says:

    I just noticed that the WWII memorial and Washington monument are not in this photo???

    [DOIG reply: That's because the balloon was tethered about halfway between the Lincoln Monument and the memorial. Airphotoslive also took images back towards the east. Don't worry; the combined images show the whole crowd.]

  53. August 31st, 2010 at 1:08 am

    Dennis says:

    10 sqft is way too conservative for a tight crowd..

    Even the park service used 2.5 sqft back in the day…which to me is mosh pit like:)

    I used several ariel pics and local shots, and used google earth maps myself, and while I agree there isn’t even enough sqft including the pool itself to support 1 million, let alone 500,000, the crowd was well pack 800 feet out on the south side of pool and in that area alone I estimated 75,000 people…

    Another simple way that I probably shouldn’t share but will is to take a known football stadium, since sitting in a seat easily equates to the normal shoulder room in a crowd, and see how much sqft the total capacity of the seats in the stadium are…
    I used this method to get 875,000 for Obama inauguration, which seems to be on par with everyone else..

  54. August 31st, 2010 at 4:21 am

    Thomas Ray says:

    Gee, looking at all the pics, the crowd looked like a typical gathering of football fans during a Tennessee home game vs. the Gators! No politics here… Go Gators!

  55. August 31st, 2010 at 7:07 am

    Steve Doig says:

    Nice article about the crowd counting controversy by Charlie Petis in the Knight Science Journalism Tracker hosted by MIT. http://ksjtracker.mit.edu/2010/08/30/a-journalism-professor-asks-and-answers-how-many-tea-partiers-on-the-mall-on-saturday-try-80000-whyd-we-read-300000-plus/

  56. August 31st, 2010 at 7:59 am

    Wyn Williams says:

    Amazing the amount of guess-estimates made in the media, good to see so many experts….

    Im not an expert but assume you have a good idea of what you are doing and are a professional, to me that means that although of course your figure is not exact and there may have been more (or less) people then you estimate to suggest that a professional using good images and a proven method could under-estimate the crowd by three or four times is obviously ridiculous.

    Its good to get an open opinion on the attendance with methods used and information on how you did it stated, thankyou.

  57. August 31st, 2010 at 11:29 am

    JTOv says:

    Gotta agree with some of the comments about the Beck rally not being a Tea Party rally. I don’t like Beck or Palin. I personally find them frightening, but I would consider myself exceptionally sympathetic to the Tea Party. Somebody likened it to the Promise Keepers’ rally about a decade ago, which seems like a fair enough comparison.

    Anyway, thanks for explaining your methodology and replying to the comments above. Very interesting, by any measure.

  58. August 31st, 2010 at 4:28 pm

    Jeff says:

    Hi GreginIowa:

    leftcoastrebel.com posted this link to many pictures at ground level for the event


    In these pictures there are easily 3 feet by 3 feet for every person in every picture shown here. Much more in some of them. That means at least 9 square feet per person. Doig’s estimate of 10 square feet per person doesn’t seem to far off in my opinion.

  59. August 31st, 2010 at 4:46 pm

    Craig Aikin says:

    Good job. I am a local (northern VA) and I am surprised that nobody has thought about the fact that it was a beautiful day in D.C., the last big week end of the summer before school starts, several different events occurring at the same time or the number of tourists that would be in the area as a matter of fact. Has anyone taken a head count on a weekend when no events are happening? Just curious.

  60. August 31st, 2010 at 4:48 pm

    Dnanderson says:

    Sorry I just looked it up- 510,000 far and above any day this month (Google Washington metro ridership)

    [DOIG reply: Actually, about 180,000 above the normal ridership for the day. Even if you assume that all of the extras went to the rally, those who rode in pretty assuredly also rode out when it was over. So that's about 90,000 extra people -- not nearly enough to support the claims of >300k.]

  61. August 31st, 2010 at 5:02 pm

    PHLippel says:

    For some independent data, one can ask about how the people got there. Metro reported about 180,000 excess trips for the entire day, relative to an ordinary summer Saturday. There was another rally, and a crowded baseball game that evening, tha may have contributed to the excess. Some people may have gotten there by other means, but Metro was the suggested route, and I haven’t seen any reports of major traffic jams.

    180K trips is pretty reasonable for 70k to 90K attendees(two trips per person minimum, many will have taken additional rides some time during the day). And it’s pretty hard to square 180K metro trips with 500K attendees.

  62. August 31st, 2010 at 6:03 pm

    Carole Joyce says:

    I can attest to the high density of the crowd. We were staked out near the fence around the Reflecting Pool. My cousin was affected by the heat and laid down. My daughter
    then had to stand over her body.

    We refrained from drinking much because the distance to the potties-not far- was a laborious trip. You had to search for every spot to take a step and I feared falling on sleeping babies or starting a domino like collapse of the multitude.

    We decided going back to our original spot was too arduous and ended up far away where we could no longer hear, but had some shade and breathing space.

    [DOIG reply: Yes, I can certainly believe what you are describing in that area around the Pool; I could see that in the images. But the fact that you were able to walk, albeit carefully, in that area shows that it was about the 10 sq ft per person density that I used there. If the mosh-pit densities that some are insisting on in fact were there, then your cousin wouldn't have been able to lie down.]

  63. August 31st, 2010 at 9:24 pm

    Tsu Dho Nimh says:

    Interesting … I worked backwards, from the area occupied by the crowd and the figures for typical crowd densities that Professor Jacobs worked out. To help you visualize this, imagine the crowd densities in a 2-car garage of 400 square feet. A loose crowd is 40 people, a dense crowd is 89 people, and a mosh pit crowd is 160 people in the garage.

    Given the acreage of the area the crowd was occupying (as seen in Beck’s releases photos, flickr, etc), I calculated possible attendance numbers: “If the entire 38-acre rally area was completely full of people standing at a uniform density, loose crowd density means 165,500 people (4356 x 38) were there. A dense crowd would be 367,840 people (9,680 x 38). Jammed into mosh-pit togetherness, you could squeeze 662,112 people into the rally area (17,424 x 38).

    If Bachman’s million people had been there, each attendee would have had 1.7 square feet of standing room. That’s the equivalent of stuffing 235 people into a 2-car garage, which common sense will tell you isn’t going to work.”


  64. August 31st, 2010 at 9:45 pm

    Tsu Dho Nimh says:

    OOPS: Forgot the footage estimates: “Loose crowd needs 10 square feet per person. A more tightly packed crowd fills 4.5 square feet per person. A truly scary mob of mosh-pit density would get about 2.5 square feet per person.”

    That’s with people standing up. “Festival” or “Picnic” seating takes more (how much more would be a good study for someone’s thesis), and lawn chairs would also take more.

  65. September 1st, 2010 at 1:35 am

    NewDaddyDave says:

    Guys, this company may be right. I don’t really care, the mass of humanity was huge be it 80,000 or 200,000 or more.

    But if we are to take this company seriously they should post ALL the full size images captured and let other experts evaluate the time of day the shots were taken, crowd density, etc.

    Heck this could be the best advertisement this company could EVER get. Or… if frauds, they would be exposed.

  66. September 1st, 2010 at 1:43 am

    Jeff Bell says:

    One way to estimate crowd size is to compare it to other large crowd events that document their seating capacity. Having lived in Indianapolis IN and attended several Indy 500 races over my 50 years (plus being at the 8/28 event) my sense was the event attendance was equal to or greater than an Indy 500 race. IMS has fixed seating at 257,000 with most grandstands between 25-45 rows deep. Infield seating raises capacity to 400,000. At 8/28 it was nearly impossible to move through the crowds in the grass as most were shoulder to shoulder vying for the best clear view of the stage or the jumbotrons. At an Indy 500 you have plenty of room in between rows to enter and exit your seat. See my graphic at http://www.askjeffbell.com/images/HonorAttendance4.jpg for a rough comparison of the 2 venues and attendance capacity.

  67. September 1st, 2010 at 1:53 am

    NewDaddyDave says:

    We did go to the rally. We got there about 11:20, we wound up sitting about 10 yards in front of the Washington Memorial. I saw the balloon going up to take photos twice over the field off to the side. But I can’t remember the exact time it went up.

    When we tried to go about 100 yards or so in front of us it was way too tight for comfort, kids playing accidentially hitting my wallet (pet peeve of mine), bumping into others just trying to move around, I took my family back up close to the monument where we had pleanty of room to spread a blanket, and actually feel a bit of a breeze.

    I hope the publish the full size images, and the claims will easily be verified or proven false. If the company is credibile they could offer their images to the public. Heck for the attendees like myself I’ld buy high res images of my family in attendance of this event. He could probably make millions on just that alone if he sold them for $50 for a poster size image for a given location and time.

    Attendees and people who wish they could have attended would buy these full size images.

  68. September 1st, 2010 at 5:33 am

    Mekhong Kurt says:

    This was fascinating, especially the explanation of your methodology. I have no expertise in estimating crowds from aerial photos, but I did work in security for several years, and on occasion was involved in trying to get some sort of rough, inside-a-reasonable-range guesstimate of crowd size, and your estimate seems far more reasonable than one much higher (or much lower, had there been any of those). I know your estimate must disappoint a great many actual attendees (as opposed to tourists, people there for other reasons, etc.), but even Beck’s estimate of 300k-500k is way out of reasonable range, while the 1 million is downright wild (and laughable).

    Regarding the objections to calling this event a “Tea Party” one, well, then someone needs to tell those I’ve read in scores of comment threads who self-identify as Tea Partiers and insist that virtually *everyone* there was a Tea Partier. I must have seen at least 180-200 such claims just so far. And there’s the fact that Beck and Palin (especially Palin) are closely linked with the Tea Party, so it’s reasonable to assume a sizable number Tea Partiers would show up I strongly doubt those claims — I imagine some fair number of onlookers were there to gawk, not to support Beck and/or Palin.

    In any case, I enjoyed this piece and most of the comments.

  69. September 1st, 2010 at 6:18 am

    Fulbright in Portugal » Blog Archive » Crowd counting (wrapup) says:

    [...] About me « Counting heads [...]

  70. September 22nd, 2010 at 2:58 pm

    Ken J says:

    I hope you also are called on to estimate the crowd size at the upcoming rally by Stewart and Colbert. The comparison of the two different crowds will certainly fuel a lot of discussions in the future.

  71. October 30th, 2010 at 6:44 pm

    Patty Jones says:

    I, too, hope you will count heads for the Rally to Restore Sanity, happening right now in Washington D.C.

  72. October 31st, 2010 at 5:47 pm

    Brian says:

    I was debating how many people were at glen becks rally with one of my family members who had actually gone to the event. When I showed her this website, she told me that the picture shown here must have been taken very early in the day. She actually went to the event and stood in the upper left area of this picture. She remembers it being crowded but this picture shows a sparse area. Do you happen to know what time the pictures were taken that you used for your estimates?

  73. November 1st, 2010 at 6:03 pm

    Steve Doig says:

    As noted in my posting, the shots were taken right around noon, at the height of the rally.

  74. November 2nd, 2010 at 4:19 am

    Jay says:

    I just looked at photos from the Beck Rally at http://www.leftcoastrebel.com/2010/08/photos-aerial-pictures-of-glenn-beck.html to compare with my experince from the midst of the Stewart/Colbert Rally.

    We were much more densely packed than the people in the Beck crowd photos were. I can see space between people here; some folks are standing with their arms akimbo; I see people seated in camp chairs or with their gear arrayed around them on the ground. There was no way we could have done any of this at the Oct. 30th Rally. I literally could NOT move in any direction as we were shoulder to shoulder where I was standing – mid-Mall at 7th Street. I never felt like I was about to be crushed, but was glad that, as knocked about as I was, I never fell beneath all those feet. (Don’t get me wrong; the knocking about was from the domino effect of people trying to move when they couldn’t – not from discourtesy.)

    So the density of the crowd was quite tight down the center of the Mall. I also know that, due to the crowd pressure, a number of people left the Rally after Stewart & Colbert initially spoke and likewise, due to complexity of transporting so many people on buses, a bunch didn’t make it to Washington until well after 1P. (For those who could move), it was a crowd in flux.

    Even though the US Park Police no longer releases “official” crowd numbers, surely they must still be calculating them as a practical management tool?

  75. November 2nd, 2010 at 10:34 pm

    deathbymedia says:

    Thank you professor for your thorough calculus. For the last few years, it seems like people wish to go with their gut feeling to estimate anything and everything. Perhaps it is time to bring back scientific methodology back in to the equation.

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