Monitoring legal pot: How do we know if it works?

It’s going to be tough to quantify how this major social policy change is affecting everything from school suspension rates to traffic fatalities
The Washington Post / AP (US)
Wednesday, June 10, 2015

Dozens of government officials and researchers from a half-dozen U.S. states and a few countries that have legalized marijuana or are at least thinking about it are gathering in Washington state this week for meetings focused largely on one question: How do we know if it’s working? Organizers say it’s crucial to get a better handle on what data are being collected about the impacts of legalization and to consider what further research is needed.