More people died in the aftermath of the Fukushima, Japan nuclear accident from the subsequent shutdown of the country’s nuclear power than from the disaster itself, according to a new study.

Within 14 months of the accident, the government shut down the operation of all of the country’s nuclear plants. That power was replaced by imported fossil fuels, leading to an increase in electricity prices by as much as 38% in some regions, making it unaffordable for certain energy users. The reduction in energy consumption led to an increase in deaths from cold weather, economists at Columbia University, Nagoya City University, and the University of Verona concluded in the paper circulated Monday by the National Bureau of Economic Research. The research has not yet undergone peer review.