Has Donald Trump the candidate and president-elect written some campaign checks on the U.S. economy that President Trump can’t cash? The odds—and history—say that he has very likely over-promised and will under-deliver, according to a transportation economist who, coincidentally, was a University of Pennsylvania classmate. But, basically, that makes Trump just like every other president. And that doesn’t mean the Trump economic team won’t try, or that White House policy won’t have an impact on trucking.

Noël Perry, principal at Transportation Economics and a partner at FTR Intelligence, explains what to expect in the next four years in this Inauguration Day Q&A.

Historically, how much difference does White House economic policy make?

PERRY: This is highly debatable. Traditional economists think there’s a huge effect and politicians, when times are good, they think they did it; when times are bad, they say it’s the economy. So in their view, the president has immense power in upturns and no power in downturns.

But the evidence says they have very little power. Did George W. Bush start the Great Recession? No. Did Obama get us out? No. Is there any difference in the policies? No.

If you compare Hillary Clinton and Trump, both are profoundly Keynesian in the sense that they believe the president—and the government—has a lot of effect on the economy. They both ran on that, and both would address it in their policy. The only difference between Clinton and Trump is she would tend to spend more and he would tend to do more tax cuts. The effect on the federal deficit would be bad in both cases—and from what they proposed, his effect on the deficit would be worse.

The one big difference is the matter of regulation. The Obama administration was relatively aggressive on climate change and greenhouse gas reduction. Trump won’t be. And it’s probable the degree of enforcement will be more relaxed.