Having happily enjoyed an extra hour of sleep, I just returned to standard time. So too did more than 300 million Americans in every state except Arizona and Hawaii.
But should we “spring forward” next March?
Consumer Spending
With the energy savings of daylight-saving time (DST) having been pretty much debunked, the other reason for the time switch is shopping. To see if more daylight increases consumer spending, the JPMorgan Chase Institute compared 350 million transactions in Los Angeles and Phoenix. Because LA does the DST/standard time switch while Phoenix does not, researchers believe they have some causation evidence.
The Results
During the thirty days after DST began in LA last March, per capita consumer spending rose by .9%. However, after it ends in November, we can expect a reversal. You can see below that the 3.5% pullback far exceeded that initial .9% boost:
Because the data reflects fewer transactions, the number of trips to the store has probably decreased. The biggest losers though were groceries while restaurants were minimally affected. Researchers hypothesize that the reason was less daylight. They do note that the numbers differ when San Diego and Denver were each compared to Phoenix. However, all three data sets confirm that DST does not have a consumer spending benefit.
Productivity
When we lose an hour during March, productivity declines:

Safety
Early darkness can mean less pedestrian safety:

Our Bottom Line: Consumer Spending and Productivity
In different ways, consumer spending and productivity are both crucial for our economy. As 70% of the GDP, what you and I spend sustains current economic output. However, productivity is what propels growth.
Looking at the numbers, few people are worrying about consumption expenditures. But, at 1.3%, productivity growth has been a concern:
Perhaps the productivity impact is the reason to eliminate “spring forward and fall back.”
My sources and more: WSJ always has a good DST article and alerted me to the JPMorgan Chase Institute report.