加州大學柏克萊校區的經濟系助理教授莫瑞第(Enrico Moretti)表示，嚴寒天氣引起的死亡人數「非常的多」；此外，加州大學聖塔芭芭拉(Santa Barbara)校區的經濟系助理教授德軒尼斯(Oliver Deschenes)在其2007年12月發表的著作中表示，「極端天氣型態與死亡率及移民人數相關。」
Fatalities in the continental United States tend to climb for several weeks after severe cold spells, numbering 360 per day and 14,380 per year, according to a new study co-authored by two University of California economists.
Deaths linked to extreme cold account for 0.8 percent of the nation's annual death rate and outnumber those attributed to leukemia, murder and chronic liver disease combined, the study reports.
Cold-related deaths reduce the average life expectancy of Americans by at least a decade, it says.
The numbers are "remarkably large," said Enrico Moretti, a UC Berkeley associate professor of economics, and Oliver Deschenes, an associate professor of economics at UC Santa Barbara, in a December 2007 working paper, "Extreme Weather Events, Mortality and Migration."
Cities recording the biggest numbers of cold weather-related deaths include Chicago, Detroit, Minneapolis and Cleveland, according to Moretti and Deschenes.
They estimate that up to 3.2 percent of the annual deaths in those cities could be delayed if people reduced their exposure to extremely cold weather.