April 28, 2015 9:35AM

Haddock and Polsby On How Riots Occur

"This is not justice. This is just people finding a way to steal stuff," Carron Morgan, cousin of Freddie Gray, told Kevin Rector of the Baltimore Sun yesterday.  That's one of the most clear-headed interpretations of yesterday's mob violence in Maryland's largest city, which followed the convergence of hundreds of youths at 3 p.m. outside Mondawmin Mall, a shopping center on the city's west side that also serves as a hub for bus service. In the resulting tumult, groups of rioters burned police vehicles, looted stores and restaurants, and injured more than a dozen Baltimore police officers with flying missiles. 

More than twenty years ago in the Cato Journal, distinguished law and economics scholars David Haddock and Daniel Polsby published a paper entitled "Understanding Riots" that's still highly relevant in making sense of events like these. Employing familiar economic concepts such as opportunity cost, coordination problems, and free-rider issues, Haddock and Polsby help explain why riots cluster around sports wins as well as assassinations, funerals, and jury verdicts; the group psychology of rioting, and why most crowds never turn riotous; the important role of focal points (often lightly policed commercial areas) and rock-throwing "entrepreneurs" of disorder; the tenuous relationship between riots and root causes or contemporary grievances; and why when a riot occurs the police (at least those in places like the United States and United Kingdom) seldom manage to be in enough places at once, more or less by definition.

The H&P paper helps explain why so many of the memes of the past 24 hours are off base: the "protests turn violent" headlines (yesterday's riots broke out in different places from where there had been demonstrations), the "Freddie Gray's family is horrified" stories (irrelevant since this riot, like most, had little to do with sending any message of protest), and, of course, the "what about sports riots?" meme (yes, the riots yesterday have a lot in common with English soccer riots, and it's important to understand why.) "Authorities looking for ways to explain why trouble has broken out on their watch sometimes ascribe exaggerated organizational powers to 'outside agitators,'" Haddock and Polsby write. (Check.) 

In reaction to yesterday's events, pundits have tended to bark up a number of wrong trees, such as the supposed permission-giving remarks of the city's Mayor, Stephanie Rawlings-Blake. (Not really, as Dave Weigel explains.) Others imagine that the technical advances of recent years -- whether the availability of social media by which rioters can share intentions, or the ubiquity of surveillance cameras in public places -- will fundamentally alter the balance between the riotous impulse and public order. Before you make up your mind on such questions, go read Haddock and Polsby.