In the United States and Great Britain (but not in Sweden) the number of car crashes are up when our sleep time goes down by one hour right after daylight saving time (DST).
Where are we going? To why we should be debating DST.
DST Car Crashes
If several studies are correct, this is the week that we can expect traffic accidents and perhaps fatalities to rise temporarily. Based on statistics from 2002 to 2011, there could be a 5.4-7.6 percent increase in crashes during the week after DST that equals a 10-year total of 302 deaths. The theory is that sleep-deprived people get pushed over the edge when they lose that hour.
These are the results of a Canadian study covering 1991-1992 that found DST generates more accidents but not deaths:
The DST idea has been around for a long time. In 1784, Benjamin Franklin suggested more morning light would let us use fewer candles. And, for some reason, DST history commemorates George Vernon Hudson, a New Zealand entomologist who, in 1895, wanted more evening light to study his insects.
In the U.S., we have to look to 1918 when the Congress included a DST clause in time zone legislation. Hoping to move the clocks forward every May 31, instead they created a huge flap. On one side, farmers objected saying their cows could not be milked and their work could not begin in dark wet fields while baseball team owners cheered that later games would boost attendance. Convinced that more women would shop after work, the founder of Filene’s department store was also delighted.
In 1919, the Congress wound up rescinding DST and then went back and forth until the Uniform Time Act of 1966 and the Energy Policy Act of 2005 made it the law for (most of) the land. The problem though is that DST’s rationale relates to energy conservation and current research indicates that DST could even increase energy consumption.
In addition, while other studies connect sleep deprivation related to DST to diminished worker productivity, we have evidence that more evening light reduces crime and extends exercise time.
Our Bottom Line: Cost and Benefit
You can see that spring-forward/fall-back is a real “on the one hand but then on the other” issue. On the plus side we have crime and exercise while the negatives relate to car safety, worker productivity and energy conservation.
As economists we can hope that future DST policy is based on whether its benefits outweigh the costs.