The Returns to Speaking a Second Language

OLS regressions with a complete set of controls to minimize concerns about omitted variable biases, propensity score methods, and panel data techniques all lead to similar conclusions. The hourly earnings of those who speak a foreign language are more than 2 percent higher than the earnings of those who do not. The authors obtain higher and more imprecise point estimates using state high school graduation and college entry and graduation requirements as instrumental variables.