雾霾对地区GDP增长率的影响：抑郁情绪的中介效应

The Influence of Smog on the Ratio of Regional GDP Growth: Mediating Effect of Depression

环境污染导致的天气变化对人的身心健康和社会发展都会产生重大影响。本研究以心理学的视角探讨雾霾天气是否会使人产生抑郁情绪,降低工作效率,进而影响社会经济发展。方法:收集2013~2015年中国大陆27个省会城市及4个直辖市的PM2.5浓度、抑郁指数及地区生产总值增长率。采用百度统计平台基于关键词"抑郁"搜索量合成的抑郁指数作为抑郁情绪指标。结果表明:(1)2013~2015年各地区的PM2.5浓度与抑郁指数正相关显著(r=.33,p<.01),抑郁指数与地区GDP增长率的负相关显著(r=-.37,p<.01);(2)抑郁指数在PM2.5浓度和地区GDP增长率间起完全中介作用。(3)当lag=-6时,上海市2013年1月到2015年12月PM2.5浓度和抑郁指数的互相关系数最大(rR=.38,p<.05)。结论:雾霾天气可能会使人产生抑郁情绪,进而对经济增长产生负面影响。

In recent years, smog has generated serious influence on Chinese people’s life and social economic development. Although scholars have been focusing on the potential pollution with economic growth, only a few have studied the negative influence of environmental pollution on people’s emotion and behavior, which may react upon economy. Some studies indicate that air pollution results in depression and affects people’s mental health. This study attempts to construct a mediating model revealing the influence of environment on productivity from a psychological perspective. It is assumed that smog can lead to depression, reduce work efficiency and then influence regional economic development. By means of the big data method, it is possible to study the influence of individual psychological behavior on macroscopic social phenomenon. In addition, the relationship between smog and depression is analyzed longitudinally using cross-correlation.Baidu Index is a statistic of the weighted sum of keyword searching frequency based on Baidu web search. The depression index provided by Baidu using ＂depression＂ as the keyword is adopted as the proxy variable of depressed emotion. After collecting the annual average of PM2.5 densities, depression indices and GDP annual growth rates of 31 regions in China's Mainland during 2013 to 2015, the correlations among these three variables are calculated. Then, the mediating effect is tested by taking PM2.5 densities as the independent variable, regional GDP growth rates as the dependent variable and depression indices as the mediated variable. In addition, the monthly average of PM2.5 densities and depression indices in Shanghai during 2013 to 2015 is analyzed to examine the lagging effect of PM2.5 densities on depression indices via cross-correlation.The results show that：（1） From 2013 to 2015, there is a significant positive correlation between PM2.5 densities and depression indices in these regions（r =.33, p 〈.01）, and the negative correlation between the depression indices and the regional GDP growth rate is also significant（r =-.37, p 〈.01）;（2） Depression index plays a complete mediating role between the PM2.5 density and regional GDP growth rate;（3） When lag=-6, the PM2.5 densities correlated significantly with depression indices（r =.38, p 〈.05）, which indicates that the variation of depression indices lagged behind the change of PM2.5 densities and the correlation reaches its maximum with a 6-month lag.The relationship between PM2.5 densities and GDP growth rates can be influenced by government’s macroeconomic regulation and economic environment. However, the negative influence of smog on people’s emotion exists consistently with certain period of lag. Moreover, depressed emotion can negatively influence GDP growth rate. The complete mediating effect of depression index between PM2.5 density and GDP growth rate indicates that smog may contribute to people’s depression and then affect economic development, which to some extent, reveals the mental mechanism underlying the macro social phenomena.