I'm not a big fan of Daylight Saving Time (DST) for several reasons. Mainly, I hate the fact that the sun goes down an hour earlier during an already short-winter day. I always figure that this undermined the justification of DST as an energy saving device. After all, I need to turn on my lights in the evening an hour earlier, and this is not counterbalanced by energy savings in the morning (I don't think I wake up early enough!).
A new working paper by Matthew Kotchen and Laura Grant attempts to generate some estimates surrounding DST and energy savings. Here is the abstract of their paper:
The history of Daylight Saving Time (DST) has been long and controversial. Throughout its implementation during World Wars I and II, the oil embargo of the 1970s, consistent practice today, and recent extensions, the primary rationale for DST has always been to promote energy conservation. Nevertheless, there is surprisingly little evidence that DST actually saves energy. This paper takes advantage of a natural experiment in the state of Indiana to provide the first empirical estimates of DST effects on electricity consumption in the United States since the mid-1970s. Focusing on residential electricity demand, we conduct the first-ever study that uses micro-data on households to estimate an overall DST effect. The dataset consists of more than 7 million observations on monthly billing data for the vast majority of households in southern Indiana for three years. Our main finding is that -- contrary to the policy's intent -- DST increases residential electricity demand. Estimates of the overall increase are approximately 1 percent, but we find that the effect is not constant throughout the DST period. DST causes the greatest increase in electricity consumption in the fall, when estimates range between 2 and 4 percent. These findings are consistent with simulation results that point to a tradeoff between reducing demand for lighting and increasing demand for heating and cooling. We estimate a cost of increased electricity bills to Indiana households of $9 million per year. We also estimate social costs of increased pollution emissions that range from $1.7 to $5.5 million per year. Finally, we argue that the effect is likely to be even stronger in other regions of the United States.
Interesting stuff. Another justification I heard was that DST helps ensure the safety of schoolchildren catching the bus in the morning. It would be interesting to get some estimates on welfare gains on this margin, as well.
3 comments:
my prior is that there would be zero impact on the safety of children catching buses in the morning.
"Mainly, I hate the fact that the sun goes down an hour earlier during an already short-winter day. "
DST is the time we observe in the summer, and in the fall we go to standard time. perhaps we should observe DST all year long and your winter evenings will feel longer (though winter mornings won't)? or we should change the cultural perception of time - 5 am could be the new 6 am?
this explains why DST causes greatest increase in energy consumption in the fall - before we revert to standard time from DST, the mornings are dark and even when I sleep late, I have to turn on the lights in the morning.
Jeremy - agreed.
Anon.- Good point. I mixed that one point, and thanks for the clarification. Also, your reasoning for the energy consumption results make sense: perhaps no one will be too surprised by the results of the cited paper.
Regarding changing the cultural perception of time, it shouldn't be difficult. I'm guessing there are others who will make the same mistake that I did and no idea what the "real" time is. If time is an arbitrary count-off measure to structure our day, then shifting back an hour this way or that shouldn't make too much of a difference.
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