Many commonly used treatment effects estimators rely on the unconfoundedness assumption (“selection on observables") which is fundamentally non-testable. When evaluating the effects of labor market policies, researchers need to observe variables that affect both treatment participation and...

This paper extends previous research about the determinants of reservation wages by analysing the effect of progressive income taxation on the ratio between reservation and net market wages. Based on micro data for Germany (SOEP) we show that joint income taxation in Germany which discriminates...