The Impact of Electricity on Work and Health: Evidence from a Blackout in Zanzibar∗

This paper uses an unusual month-long blackout in Zanzibar, Tanzania, to measure the effect of electricity on labor and health. Relying on special purpose household surveys I find that the power cut caused a large decline in household income among those employed in occupations that require the use of electricity. Workers relying on artificial lighting reduced work hours by an average of 8%, or 40 minutes per day. Workers relying on power specialized power tools saw steeper declines, in the order of 35%, corresponding to 2.8 hours of work per day. The blackout did not have an effect on prices, labor supply for other types of workers, or other long-run effects on work. Using birth records from a large maternity ward, I document a reduction in the average birth weight of children with in utero exposure to the blackout, and an increase in the probability of these children having Low Birth Weight. The weight reduction is correlated with village-level measures of employment in electrified sectors. The most likely explanation is a blackout-induced decline in maternal nutrition. Alternative explanations are examined, including the presence of other economic shocks, high world food prices, blackout-induced shocks to home production and food availability, maternal stress, selection of mothers visiting the hospital, and temporary fertility shifts. None of these explanations are consistent with the findings. JEL Classification: O15, O14, J29, I12