Researchers reached this conclusion by studying the federally mandated shift in welfare benefit distribution. In the 1990s, states stopped giving recipients checks—easily converted to cash—and instead allocated money to debit cards. In Missouri, this shift happened in different counties over the course of a year. A team of economists and criminologists used historical data to attribute a 9.8% crime drop to the welfare system’s adoption of electronics benefits transfer, in a 2014 National Bureau of Economic Research working paper.

https://www.wsj.com/articles/why-your-business-should-ditch-cash-1485698400