Yesterday we brought you some of the qualitative data from the Urban Institute's report on the underground sex work economy. Today, we show you above what we think is an interesting comparison between the changing size of the market for sex, guns, and drugs in the eight U.S. cities the studies cover. Conclusion: the sex market is way bigger than the drug market!

Also, apparently drug prices haven't fluctuated as much as sex and gun prices, but they have risen a lot quicker over time. The More You Know!

[Data visualisation by Reuben Fischer-Baum.]