There was a report on the DailyMail.com website on March 13, 2016 concerning demonstrations against the Brazilian government’s president (http://www.dailymail.co.uk/wires/ap/article-3490263/). The report mentioned large demonstrations in Sao Paulo, Brazilia and Rio de Janeiro. It also stated that the number of people at the largest demonstration in Sao Paulo was according to a “polling agency estimated at about 500,000 people” while “police estimates put turnout at nearly three times that number.” The article stated under a photograph of the demonstration that the “demonstrators filled Paulista Avenue.”
How can we confirm crowd size reports like this? The CrowdSize application lets anyone produce an estimate of the number of people at an outdoor event anywhere in the world. How could the app be used in this case? Below are a series of screen captures from the CrowdSize app that show segments of the entire length of Paulista Avenue in Sao Paulo assuming the demonstrators occupied the entire width of the street. The CrowdSize app uses a default density factor of 1 person/.37sm for a crowd that is very dense. If we use this high density factor for the areas along the entire 2.8 kilometer length of Paulista Avenue we come up with an estimate of 358,860 people. There could be some people in the side streets which could increase the number to close to 400,000 but the police estimates for the demonstration are very inflated.
CrowdSize gives us the ability to challenge reports from the media, promoters and “official sources” and decide for ourselves the degree of support we see for the causes that people are passionate about.