This Issue Brief introduces a measure that estimates the factors that influence firm location choice in U.S. cities. It then investigates which of these factors may best explain the variance in employment trends across a select set of Massachusetts municipalities: the small and mid-sized post-industrial Massachusetts cities that the Federal Reserve Bank labels ?working cities.? The analysis suggests that the highest correlates to economic growth are the availability of sites for development, economic development marketing, and the timeliness of municipal approvals for development projects. These results provide some indication of the extent to which these cities and others might influence their own economic futures.