This article uses various micro data sets to study entrepreneurship. Consistent with the existence of capital constraints on potential entrepreneurs, the estimates imply that the probability of self-employment depends positively upon whether the individual ever received an inheritance or gift. When directly questioned in interview surveys, potential entrepreneurs say that raising capital is their principal problem. Consistent with the authors' theoretical model's predictions, the self-employed report higher levels of job and life satisfaction than employees. Childhood psychological test scores, however, are not strongly correlated with later self-employment. Copyright 1998 by University of Chicago Press.