If there's one government mandate we can all hate together, surely it is Daylight Saving Time. Reading
this, we are reminded that DST was not intended to help farmers; urban businesses were supporters. Some further cursory googling of my own reveals that most of Indiana does not have DST
because of farming interests in that state. Then there's the energy-saving justification for DST: the article I linked to above gives a few anecdotal counter-arguments to this justification, but no data. In looking for numbers, all I could find are references to "studies from the 1970s" and, less vaguely, to a 1975 DOT study. Then I found this 2001
testimony from a DOT official to the Energy Subcommitee of the House Science Committee:
Our 1975 study concluded that daylight saving time might result in electricity savings of 1 percent in March and April, equivalent to roughly 100,000 barrels of oil daily over the two months. These savings were calculated from Federal Power Commission data for only four daylight saving time transitions -- in the winter, spring and fall of the 1974 - 1975 experiment. Due to the limited data sample, the findings were judged "probable", rather than conclusive. Theoretical studies of home heating fuel consumption identified small savings due to daylight saving time. No potential increases in travel demand and gasoline use due to daylight savings time were identified at that time. The lack of actual data precluded an estimation of net daylight saving time energy savings. (emphasis added)
The poor quality of this study doesn't seem be generally known. For example, this California Energy Commission
webpage doesn't seem to know about that "lack of actual data":
Studies done in the 1970s by the U.S. Department of Transportation show that we trim the entire country's electricity usage by about one percent EACH DAY with Daylight Saving Time.
Moreover, it's not "each day" of DST. DST doesn't start until March is over, and the only other month the DOT found energy savings was April. That leaves May through October with a big question mark.
Is there any better data out there? The California Energy Commission also did some
regression analyses that predicted that making DST year-round instead of just April-October would cut California winter electricity use by half a percent. They also predicted "summer double DST" would cut California summer electricity use by a fifth of a percent and "could save hundreds of millions of dollars" by shifting electricity use to low demand morning hours. I'd like to see a national version of this study. I'd also like to see a study that estimates the net energy savings of ending DST, rather than just the net energy savings of intensifying it.
As best I can tell, DST very very slightly more likely than not saves America energy. Does this make the inconvenience worth it? Not to me: I want my hour back, or in lieu of that, some conclusive energy savings evidence.
Update: I should point out that the DOT study only looked at energy savings in March and April because it was trying to determine the merits of having DST start earlier, not the merits of DST itself. This reinforces my point about the lack of data on the merits of DST.