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...

Perhaps it does. We propose a model in which workers with little education or in the tails of the age distribution the inexperienced and the old have more chance of job failure (mismatch). Recruits' average education should then increase and the standard deviation of starting age decrease when...