Introducing … the CKC
In almost every US state, the relationship between crime and income is strikingly clear. Since 1970, the data shows a pervasive pattern similar to an inverted U-shape: crime increases with per capita income until it reaches a maximum and then decreases as income keeps rising. Figure 1 shows income measured in the horizontal axis as real per capita GDP (2009) and the crime rate –per 100,000 inhabitants– which aggregates the seven felony offenses recorded in the FBI’s Uniform Crime Reports. The solid line is a flexible non-parametric fit of the data, and the shaded area is the 95% confidence band...