I show empirically that state wage-payment laws, which forbid deductions from wages and salaries without the written permission of the employee, constituted a binding constraint on firms’ choices to adopt automatic enrollment in 401(k) plans prior to 2006.

Using Health and Retirement Study data and a structural econometric model, we exploit variation in employer matching rates in 401(k) plans to generate new estimates of the EIS: 0.74 in our richest specification, with a 95% confidence interval of 0.37-1.21.

Using Health and Retirement Study data on contributions, earnings, and pension plans, we examine the role of liquidity constraints in explaining why employees fail to take full advantage of employer matching contributions in 401(k) plans, leaving "money on the table."