California Lead Visual

Inequality, Poverty, Abortions, Crack, and Culture. All of these have been considered as factors that increase criminal behavior. But establishment criminologists seem to have overlooked a fring element to crime: Lead. Among all theories that attempt to explain crime, no factor explains the dramatic rise and equally dramatic fall of crime in the late 20th century. Only changes in environmental lead levels from gasoline can explain the huge jumps in crime interationally, and across states within the US. This graphic seeks to further explore the relationship between changes in lead levels and crime on a county by county basis in California. Does the relationship between lead and crime still hold in the early 21st century? The color coded counties will show you the strength of the relationship between lead and crime in each county. Mouse-over the "statewide" button to see how the relationship holds for the entire state of California.

Weird huh? You'll notice that on a country by county basis, the relationship between lead and crime in California does not look that strong at all. However on the statewide level, the relationship is extremely strong. This counter-intuitive outcome is from something called the "Simpson Effect." The Simpson Effect is a statistical phenomena where combining multple datasets can actually yield the opposite relationship the individual subunits show.