The Effect of Employment Protection on Teacher Effort
利用芝加哥公立学校2004年集体谈判协议改革，发现赋予校长解雇试用期教师灵活性后，教师年缺勤率下降约10%，频繁缺勤率下降25%，主要源于教师构成变化，对年轻非终身教师有适度激励效应。
In 2004, the Chicago Public Schools and the Chicago Teachers Union signed a new collective bargaining agreement that gave principals the flexibility to dismiss probationary teachers (those with fewer than 5 years of experience) for any reason and without the hearing process typical in many urban districts. Results suggest that the policy reduced annual teacher absences by roughly 10% and reduced the incidence of frequent absences by 25%. The majority of the effect was due to changes in the composition of teachers in the district, although there is evidence of modest incentive effects for young untenured teachers.