Interested in some “used” toilet paper?

That’d be $200, on Facebook Marketplace. The online ad from Upper Darby was probably a joke — or maybe not. Toilet paper has been hard to come by these days after panicked shoppers emptied grocery store shelves of bathroom tissue. The toilet paper shortage became a meme on social media, and came to symbolize consumer hoarding during the coronavirus pandemic.

So, what happened to all the toilet paper? We asked two local experts — Deborah Small, a Wharton psychologist, and Subodha Kumar, a Temple professor of supply chain management — to explain this strange side effect of the coronavirus crisis.

Their responses were edited for length and clarity.

Why the panic over toilet paper?

SMALL: “Maybe there was one stock [of toilet paper] out somewhere and then it hit the news and hit social media, and then it kind of spiraled out of control from there. People start hearing, ‘Oh my gosh, other people are over-buying toilet paper. That means that I might not be able to get it when I need it.’ And so when they go shopping, they buy more of it. Then if everybody’s doing that, then we have this stock out situation. So my sense is, it’s not anything about the product per se. It’s more just this herd behavior of focusing, fixating on a particular product. There’s general panic, and then there’s panic over other people’s panic.”

Has something like this happened before?

SMALL: “The general phenomenon of stocking up in some uncertain time is that we all have this fundamental motive to maintain control over our environments. That’s fundamental in psychology, the need to have control. And when we go about our daily lives, most of the time we feel pretty in control, right? We have freewill. Most people can purchase things that they need when they want to. There’s not this kind of looming fear that’s at the back of their minds all the time. But when something extraordinary happens like this, then we feel out of control, and purchasing and having lots of stuff around us is one way that we can feel in control.”

So, why is there still a shortage?

KUMAR: “We have seen these kind of shortages in many different situations, like whenever we have a hurricane, but this is more global so it’s everywhere. It’s not concentrated in one region. So, I think that is making the biggest difference in terms of the supply chain of the items. Most of the time when we see this kind of crisis in Asia, the whole supply chain tries to move their inventory around. For example, they will move from one distribution center to another and they will try to fulfill the demand in that particular area. And that diverting sometimes comes with the cost. But in this case, they cannot do that.”

So there’s just too much demand everywhere at once?

KUMAR: “Most of the problem that is happening is because of the demand issue, not as much of the supplies, but there’s something in the supply that we need to consider. ... One thing that people sometimes don’t know is the difference between the commercial demand vs. the consumer demand. There’s predictions that households will use around 40% more toilet paper just because they are at home, not using it anywhere else. So a lot of business demand has shifted to consumer demand, because businesses don’t need it right now but consumers need it much more.”

Can we move the business inventory to consumers?

KUMAR: “It’s not the same product. There are several companies who only supply to businesses. They don’t supply to the consumer market at all. So that’s the first part of the problem. ... Now there are some other companies who work in both markets, like Georgia Pacific. ... But even Georgia Pacific, the material they use for the commercial brands is different from what they use for consumer brands. They use mostly recycled fiber, but for the consumer brand, they don’t use that. They use 100% virgin fiber. People are looking for what they want in the consumer market. They’re not going to get commercial product, which is available in the market. So because of all this complexity, as soon as the demand increased, they just cannot fulfill that.”

Are commercial suppliers sitting on unused toilet paper?

KUMAR: “The demand for toilet paper is very stable. So they don’t account for a lot of variations in the supply chain, because everything is almost fixed. The producing is a very fixed process. So what has happened is that for commercial supplies, they already have some over supply. But the good part is that because the demand is so certain, they don’t keep lot of buffer. So even though they have stopped, they have some extra, but it is not too much extra. They’re not keeping buffer for six months, right? Because they don’t have to.”

Why does it take so long to get toilet paper back on shelves?

KUMAR: “The biggest problem why, in this kind of situation, companies are not able to fulfill is because there’s that delay on how information is transmitted from the retailer level to the supplier level. There is always an information gap because information is not visible in real time. ... This gap could be up to 50 days or even longer in many supply chains. Because of these delays of the 30 days or so, by the time they start producing more and coming to market you see a gap.”