In Poor Sleep Makes People Poor I discussed an important paper by Maulik Jagnani showing how India’s single time zone creates a big disconnect between biological time as given by light cues and clock time. The disconnects impedes sleep patterns and reduces human capital for those most effected.
In a new paper in the Journal of Health Economics, Sunset Time and the Economic Effects of Social Jetlag Giuntella and Mazzonna show that the same types of effects can be observed in the United States.
The rapid evolution into a 24h society challenges individuals’ ability to conciliate work schedules and biological needs. Epidemiological research suggests that social and biological time are increasingly drifting apart (“social jetlag”). This study uses a spatial regression discontinuity design to estimate the economic cost of the misalignment between social and biological rhythms arising at the border of a time-zone in the presence of relatively rigid social schedules (e.g., work and school schedules). Exploiting the discontinuity in the timing of natural light at a time-zone boundary, we find that an extra hour of natural light in the evening reduces sleep duration by an average of 19 minutes and increases the likelihood of reporting insufficient sleep. Using data drawn from the Centers for Disease Control and Prevention and the US Census, we find that the discontinuity in the timing of natural light has significant effects on health outcomes typically associated with circadian rhythms disruptions (e.g., obesity, diabetes, cardiovascular diseases, and breast cancer) and economic performance (per capita income). We provide a lower bound estimate of the health care costs and productivity losses associated with these effects.
Hat tip: Kevin Lewis.