Social experiments are powerful sources of information about the effectiveness of interventions. In practice, initial randomization plans are almost always compromised. Multiple hypotheses are frequently tested. "Significant" effects are often reported with p-values that do not account for...

"In 1998 the Slovenian UI system was drastically reformed. The reform reduced the potential duration of unemployment benefits substantially and simultaneously improved employment services offered to, and monitoring of, the recipients. We find that the reduction in potential benefit duration had...