Monday, June 08, 2020

Estimating Protest Numbers

Estimating crowd sizes can be a very controversial subject. When reporting on the numbers of people attending a march or protest the media will often use estimations provided by the police. However the police may not always be impartial observers - particularly if the protests being reported on are against police violence.

One way to estimate the size of a crowd is to use maps to calculate the surface area of a crowd and then to multiply that surface area by the estimated density of the crowd. MapChecking is a very simple interactive map tool that can do this for you. It allows you to draw the surface area of your crowd, demonstration, protest, march or gathering on a Google Map. It then allows you to enter an estimate for the number of people per square meter in your crowd. Once you have entered those two variables MapChecking automatically works out the estimated crowd size.

The results can be quite surprising. Using an aerial photo of a Black Live Matter protest in Union Park, Chicago I tried to estimate the crowd size. Without using MapChecking, I estimated the number at a few thousand. However when using MapChecking, even when using a small number per square meter, the crowd is estimated as being over 23,000.

Block Club Chicago report that on Saturday June 6th 30,000 marched from Union Park to near Seward Park.

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