There had been no such increase in neighboring Pennsylvania. Standard theory would predict that New Jersey's 19 percent increase would cost jobs. But nothing of the sort happened. Like several earlier studies in Texas, California, and the United Kingdom, the New Jersey data suggested that minimum-wage increases, in some circumstances, might actually increase employment. Labor markets are not exactly like product markets.
Wage levels can influence how hard people work and how often they quit.
Pay people more, and they might work harder or display lower rates of turnover. So a higher minimum wage might raise productivity and lower recruiting and training expenses that would offset its costs. For proponents of the minimum wage, the Card-Krueger study provided a novel argument in support. If there were mild job losses, these could be made up in other ways. The Card-Krueger study drew attention both because of the stature of its authors and because of the meticulous care of their research.