In May 1981, President François Mitterrand regularized the status of undocumented immigrant workers in France. The newly legalized immigrants represented 12 percent of the non-French workforce and about 1 percent of all workers. Employers have monopsony power over undocumented workers because...

"Although economic theory predicts an inverse relation between relative wages and immigration-induced supply shifts, it has been difficult to document such effects. The weak evidence may be partly due to sampling error in a commonly used measure of the supply shift, the immigrant share of the...