The Impact of Changes in the Term of Labor Contracts on the Workers： Evidence from the Unique Panel of CHIP 2007-2008
利用中国家庭收入调查数据（CHIP）2007-2008年独特的城镇样本面板数据,通过从工人角度考察劳动合同期限变化对工人工作收入、工作时间、是否想找新工作以及幸福感的因果影响效应,结果发现：相比于合同期限无变化的工人,合同期限变为无固定期限合同的工人其工作时间和想找新工作的可能性显著下降,幸福感显著提高,但对其工作收入没有显著影响;而合同期限由无合同或短期合同变为长期合同的工人其幸福感显著提高,但对其工作收入、工作时间以及想找新工作的可能性没有显著影响;而失去无固定期限合同的工人其工作收入和幸福感显著下降,想找新工作的可能性显著提高,但对其工作时间没有显著影响;失去长期合同的工人其想找新工作的可能性显著提高,而对其工作收入、工作时间及幸福感均没有显著影响;合同期限在无合同和短期合同之间变化的工人,其工作收入、工作时间及幸福感没有显著差异。上述结论为考察《劳动合同法》影响后果的研究提供了一个新视角。Using the urban sample of the unique panel data of CHIP 2007-2008, this paper investigates the causal impact of changes of labor contracts on workers＇ earnings, working hours, likelihood of looking for a new job and their emotional well-being. The findings show that there is significant decline in working hours and likelihood of seeking a new job, and remarkable increase in emotional well-being among workers whose contracts have changed to open-ended contracts than those whose contract terms do not change, and that the change of contracts do not have significant impact on their earnings. Change from no contracts or short-term contracts to long-term contracts greatly increases workers＇ emotional well-being, but has no significant impact on their earnings, working hours, and the likelihood to look for a new job. However, there is remarkable decline in earnings and happiness, and higher likelihood of looking for a new job among those who lose open-ended contracts, but this change do not have significant impact on working hours. Loss of long-term contracts makes workers more likely to look for a new job,but has no obvious impact on their earnings, working hours and emotional well-being. Worker without contracts or short-term contracts see no significant difference in their earnings, working hours and emotional well-being. The findings provide a new perspective for the impact of Labor Contract Law.