A large and highly used number of 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 both variables that affect treatment...

Using both household and linked-employer-employee data we study the effects of works councils on individual sickness absence rates and a subjective measure of personnel problems due to absenteeism in Germany. We find that the existence of a works council is positively correlated with the...