This paper examines the relationship between family income and college enrollment, and the evidence on credit constraints in post-secondary schooling. It distinguishes between short-run liquidity constraints and long-term factors that influence cognitive and noncognitive abilities. Long-term factors, such as family resources and environment, are the main determinants of the family income-schooling relationship. While some evidence suggests that up to 4% of the U.S. population is credit constrained in the short run, the paper argues that long-term factors are more important in explaining enrollment gaps. The paper critiques arguments that IV estimates of the returns to schooling exceed OLS estimates as evidence of credit constraints, showing that such differences may be due to invalid instruments or other factors. It also finds that adjusting for long-term factors largely eliminates the effect of family income on college enrollment. The paper concludes that short-run credit constraints play a minor role in explaining enrollment gaps, and that long-term family factors are the primary determinants of schooling outcomes. The evidence suggests that policies targeting short-run constraints may have limited effectiveness, while policies that improve long-term family environments are more likely to increase college enrollment. The paper also finds that the returns to schooling are often higher than those of physical capital, but this does not necessarily indicate credit constraints. Overall, the paper argues that long-term family factors, rather than short-run credit constraints, are the main explanation for differences in college enrollment by family income.This paper examines the relationship between family income and college enrollment, and the evidence on credit constraints in post-secondary schooling. It distinguishes between short-run liquidity constraints and long-term factors that influence cognitive and noncognitive abilities. Long-term factors, such as family resources and environment, are the main determinants of the family income-schooling relationship. While some evidence suggests that up to 4% of the U.S. population is credit constrained in the short run, the paper argues that long-term factors are more important in explaining enrollment gaps. The paper critiques arguments that IV estimates of the returns to schooling exceed OLS estimates as evidence of credit constraints, showing that such differences may be due to invalid instruments or other factors. It also finds that adjusting for long-term factors largely eliminates the effect of family income on college enrollment. The paper concludes that short-run credit constraints play a minor role in explaining enrollment gaps, and that long-term family factors are the primary determinants of schooling outcomes. The evidence suggests that policies targeting short-run constraints may have limited effectiveness, while policies that improve long-term family environments are more likely to increase college enrollment. The paper also finds that the returns to schooling are often higher than those of physical capital, but this does not necessarily indicate credit constraints. Overall, the paper argues that long-term family factors, rather than short-run credit constraints, are the main explanation for differences in college enrollment by family income.