Justin Ho

They require transportation.

They're heavy.

They're spacious.

And all three of those, labor, energy, and transportation, are current sort of long-term structural pain points in the food supply chain.

The canary and the coal mine here are really the perishable food products.

One thing that made the oil shocks of the 1970s especially bad was that cars back then weren't very fuel efficient.

Daniel Sperling is a professor emeritus at UC Davis.

When I was young, a car got 13 miles per gallon.

You know, now they're getting 30 miles and some of them are up 50, 60 miles per gallon.

And that's largely thanks, Sperling says, to federal regulations that were created in response to those oil crises.

The industry has been obligated to continually supply more efficient vehicles.

But because we tend to drive our cars for a long time, the average vehicle on the road is nearly 13 years old.

Those more efficient vehicles take a while to change our overall gas consumption.

Joshua Lynn is a professor at the University of Maryland.

We still have a lot of vehicles on the road that have relatively low fuel economy.

They were produced back a long time ago when those standards were weaker.

The federal government started bolstering those standards about 15 years ago.

So as newer models keep cycling into traffic, we'll keep seeing overall fuel economy rise, says Rebecca Chez at Purdue University.

And that price at the pump?

The federal fuel economy rules have also pushed companies to make more electric and hybrid vehicles.