Hand sanitzer and face masks have been flying off store shelves as people gather supplies for the coronavirus outbreak. But there is another seemingly unorthodox commodity that has been in popular demand: toilet paper. WGBH Morning Edition host Joe Mathieu spoke with Boston University senior lecturer and economist Jay Zagorsky about why people are turning to toilet paper as they hunker down during the pandemic. The transcript below has been edited for clarity.

Joe Mathieu: What is going on with the hoarding of toilet paper? Are they worried we won't have any in a month?

Jay Zagorsky: I would say hoarding makes people feel more secure. Right now with this novel coronavirus, people are very, very scared. And if you can make sure one part of your life is secure — that you have toilet paper — you're willing to stock up a lot on it.

Mathieu: So is this just a random confluence that we all decided toilet paper was the security blanket for coronavirus? How do all people end up going in the same place?

Zagorsky: I would say behavioral economists have identified something called zero risk bias. The idea of zero risk bias is when you're faced with a lot of risky choices, you want to eliminate one of the risks. Stocking up on things like toilet paper eliminates at least some of the risk in your life.

Mathieu: Because we're not going to run out, correct? They're still making more.

Zagorsky: There are commodities that we import, but we don't actually import toilet paper. We import less than 5 percent of our toilet paper, and the toilet paper we do import comes mainly from Canada.

Mathieu: And you've seen this before. We've actually seen this happen.

Zagorsky: We actually saw this in the 1970s. During the 1970s, there was a number of shortages of things like petroleum [and] gasoline. And Johnny Carson went on TV and he said, "I read in the newspaper that there was a shortage of toilet paper." Now, that was a press release that said there might be a shortage of toilet paper and it was done by a congressman in order to drum up a little bit of support for the businesses in his district. But when Johnny Carson said there might be a shortage of toilet paper, people cleared off the shelves for an entire month.

Mathieu: Wow. We don't have something like that this time, though.

Zagorsky: No. If you go into a store late in the afternoon, the shelves are cleared out. But every morning, the shelves are restocked. If we really were in a shortage situation, they wouldn't be able to restock the shelves at night.

Mathieu: And so Gov. Charlie Baker says, hey, would you calm down, stop doing that, because if you keep hoarding, your neighbor's not going to get the stuff that they need. And that, I guess, is the nature of hoarding.

Zagorsky: That's the nature of hoarding. In economics, we call it the fallacy of composition. If I stand up at a sporting event like a baseball game, I see better. If everyone stands up, no one sees better and most of us see worse. If I overstock on toilet paper — if I overbuy toilet paper today — I might be better off. But in society, if everyone starts massively buying toilet paper, everyone's worse off.

Mathieu: Are there other things running short? Is there another toilet paper out there that we're not aware of that people are buying up and leaving shelves empty?

Zagorksy: It's pretty clear we're short on things like hand sanitizers and masks.

Mathieu: That you'd expect, though.

Zagorksy: That we'd expect. Many of those products are not made in the United States; we import a lot of them. And demand for those things have increased because we're all washing our hands a lot more. My hands are almost rubbed raw for how many times I wash them with soap.

Mathieu: And that's what you would expect. Now we're also seeing people stock up on booze, there are lines out the package store, and marijuana now that you can buy it legally. There were a couple of hundred people in front of the dispensary over the weekend in Brookline. Is that the same phenomenon? Is that more of a cocooning type of economic effect?

Zagorsky: I think it's the same thing. For some people, they feel better knowing there's a large stock of toilet paper in the house. For others, knowing there's a large amount of wine or vodka, that will make them feel more secure.