工作时间对劳动者健康影响的阈值效应分析

Threshold Effect of Working Hours on Health

目前长时间工作对健康造成的不良影响已引发了社会的普遍关注,但是这个变化过程是渐进的还是突变的,是否存在阶段性变化,现有研究尚无定论。本文基于2016年中国家庭追踪调查数据,首先检验了工作时间对不同类型劳动者健康的影响,再应用夏普利回归方程分解方法确定了工作时间对不同类型劳动者健康影响的阈值。研究结果表明,工作时间对劳动者身心健康具有显著的负向影响,即随着工作时间的增加,无论是脑力劳动者还是体力劳动者,其身心健康水平均呈显著下降趋势。相对于体力劳动者,工作时间对脑力劳动者身体健康的影响程度更大。此外,工作时间对劳动者身心健康的影响存在明显的阈值效应。当脑力劳动者周工作时间超过40小时,体力工作者达到或超过50小时,劳动者身体健康状况明显恶化;达到或超过70小时,无论是脑力劳动者还是体力劳动者,其身体健康和心理健康状况都进一步显著恶化。

The adverse effects of long working hours on health have aroused widespread concern in the society. However, the existing literature has not yet concluded whether the effects take a gradual, discontinuous, or even a phased process. Using 2016 China Family Panel Studies data, this paper applies ordered logit model to analyze effects of working hours on health of different types of workers and uses Shapley decomposition to identify corresponding thresholds. The results indicate that overtime work is quite common in China, especially among manual workers. There are strong associations between working hours and workers’ health. With increasing working hours, workers suffer a significant decline in both physical and mental health, and the effect of working hours on health of mental workers is greater than that on health of manual workers. About thresholds of working hours, the results suggest that when the weekly working hours of a mental worker exceed 40 hours, or over 50 hours for a manual worker, their physical health will be significantly worsened. Regardless of workers’ type, when they work 70 or more hours weekly, both of their physical and mental health will be significantly damaged.