The Impact of Length of the School Year on Student Performance and Earnings: Evidence from the German Short School Years
利用1966-67年西德缩短学年（约少上三分之二学年）的自然实验，发现短学年增加了小学留级率、降低了高中入学率，但对成年后的收入和就业没有负面影响。
This article investigates how changing the length of the school year, leaving the basic curriculum unchanged, affects learning and subsequent earnings. I use variation introduced by the West German short school years in 1966-7, which exposed some students to a total of about two thirds of a year less of schooling while enrolled. I find that the short school years increased grade repetition in primary school and led to fewer students attending higher secondary school tracks. On the other hand, the short school years had no adverse effect on earnings and employment later in life. Copyright 2007 The Author(s). Journal compilation Royal Economic Society 2007.