The sex workers of Tampa, Florida, and Charlotte, North Carolina, can get ready for a spike in business at the end of next summer: the Republican and Democratic National Conventions, respectively, are coming to town. In the last electoral cycle, the political jamborees were held in Denver and Minneapolis – and there seems to have been a coincidental surge in the local market for sex.

The economists Scott Cunningham and Todd Kendall discovered this by examining advertisements in the “adult services” section on Craigslist, the online ad service. (Craigslist has since closed down this section.)

Using postings in Seattle and Philadelphia as a control group – these cities did not have almost 50,000 visitors descending on them for a few days – the economists estimated that advertisements selling sexual services increased by 29-44 per cent in Minneapolis during the Republican visit and 47-77 per cent in Denver when the Democrats arrived. I’m not going to make jokes about oversexed politicians, largely because the majority of visitors appear to have been journalists.