Many studies examine the importance of teachers in students' learning, but few exist on the contribution of principals. We measure the effect of principals on gains in primary test scores in North Carolina and estimate the standard deviation of principals' value added to be 0.12 -0.17. We find...

Despite a strong interest in entrepreneurship, economists have devoted little attention to the role of health insurance availability. I investigate the impact of a unique policy experiment - New Jersey's Individual Health Coverage Plan - on self-employment. Implemented in August 1993, the IHCP...