Riots must be due to basic forces underlying human and social behavior since they have happened throughout history in all parts of the world. Recent years have seen riots not only in Britain, but also in France, and China, to take only a few examples. As Posner indicates, the United States has a long history of riots that date back to the revolutionary period in the 18th century. I will discuss a few ways to reduce the incidence and severity of riots, but the pervasive social behavior that cause riots will always be lurking in the background.
To understand riots it is useful to divide the population of any country or city into three largely distinct groups. Many men and women will basically obey the main laws under the vast majority of circumstances, no matter what others may do. A minority of individuals will engage in criminal behavior, such as theft, if the gains are large enough, and if they are not likely to be substantially punished. The third group comprises individuals who are law-abiding if people around them are law-abiding, but who can be triggered by events and the behavior of others into various acts of lawlessness.
The first group will essentially never participate in riots, while criminals will always participate if they see opportunities to steal and rob. Since riots are social phenomena, the third group of individuals forms the backbone of rioters since they may join in when others are rioting, and refrain from vandalism and stealing if others also refrain. The crucial point in understanding riots is that behavior dependent on what others do has an inherenly unstable component. This means that many overall outcomes are possible depending on various precipitating events. For example, since the willingness of some white families to live in a neighborhood may depend on how many white families live there, sales of some homes in the neighborhood to black families will encourage other white families to move out. Their departure in turn will encourage still other white families to move to other neighborhoods. The result is the well-documented phenomena of neighborhood “tipping” in a short time from having mainly white families to having mainly black families.
In the same way, riots develop when some events mobilize the social forces that attract some individuals to participate because others are. The English riots apparently started because London police shot a black male. Soon not only blacks but also many whites were rioting in London and a few other cities. The French riots in the fall of 2005 in Muslim suburbs started with the deaths of two Muslim teenagers outside of Paris indirectly blamed on the police, and soon engulfed many Muslim young men. Recent Chinese riots have resulted from the government’s confiscation of the property of farmers to use for the building of factories and infrastructure. Before long, many farmers with the same or other grievances against governments joined the rioting.
Fortunately, the behavior that induces individuals to join a riot when others are rioting is not immutable, but depends on many circumstances and on incentives. Rioters are mainly younger men, particularly those who are unemployed and have lots of time on their hands. The high unemployment rates of young French Muslim males who were not integrated into the French economy were a major factor behind the 2005 rioting there. The likelihood that many rioters will be apprehended and punished affects the willingness of many to participate in riots, especially individuals with much to lose from being arrested and punished. Police crowd control techniques and police efforts to address grievances in minority neighborhoods are also important in preventing some riots, or at least ending them more quickly once they have begun.
Since riots are the result of social behavior, it is no surprise that Facebook, Twitter, and other Internet-based forms of social communication played a part in generating the English riots. These social networks have been crucial in the “riots” against the autocratic governments of Egypt, Tunisia, Bahrain, Syria, and other Arab countries. These were political demonstrations against unpopular governments, but analytically they have similar behavioral structure to the economic and social riots in democratic countries. The ease of communicating over the Internet will surely lead in the future to greater group protests.
Since the social behavior that underlie riots are a fundamental part of human behavior, one cannot expect riots to disappear, especially given the growing power of social networks. However, reasonable steps can reduce their incidence and destructiveness. Firm but fair enforcement of laws by police and other government officials will reduce the likelihood of the sparks that often start riots, and will also raise the cost to those who use riots to steal and vandalize property. Good employment and education opportunities for the poor and minorities will increase their confidence that they can have a satisfying economic future if they obey reasonable laws and work hard. Democratic access to political protests and protection of personal and other property will improve respect for the laws.
Especially in the Facebook age, none of these and other sensible actions will eliminate riots. However, a good economic, social, and political environment will significantly cut down the incidence and cost of riots. That itself would be a major achievement.