When state and local leaders began issuing stay-at-home orders in mid-March to limit the spread of the novel coronavirus, grocery and big-box stores saw their shelves picked bare as shoppers prepared to hunker down at home. 

Several months into our pandemic-era reality, the panic-buying phase has passed, and shoppers are reporting some improvement in what they’ve been able to find at stores from those early days. NPD Group found in recent surveys that 37% of shoppers had experienced out-of-stocks when shopping for food in the month of May, down from 48% who said the same for the month of April.

But you need only take a trip to your local supermarket or try to fill your digital grocery cart to see that the out-of-stock situation hasn’t returned to pre-pandemic patterns. So what is going on? It varies from item to item, but here are some reasons you might still be having to substitute – or do without – some of your go-to groceries: 

Dislocation of demand: This is a problem I’ve come to call the Toilet Paper Problem, because it is the hard-to-find item most frequently used to illustrate this particular shock to the consumer-product ecosystem. Before the pandemic, people used the bathroom in all sorts of places: at home, offices, schools and restaurants. Now, though, a lot more bathroom trips are happening at home, meaning so-called retail toilet paper – the Charmin or Cottonelle you buy at the grocery store – is needed in greater quantities, while the giant commercial rolls at office towers or sports arenas are needed in smaller quantities. It is simply taking manufacturers and retailers time to adapt to a world where people are spending less time in commercial and institutional spaces and more time at home. This is why, for example, you may have encountered out-of-stock pasta, rice or beans – people are eating more meals at home, and the supply chain that provides those goods in bulk to restaurants, cafeterias and hotels can’t turn on a dime to change their pack sizes and forge relationships with retailers.

The rise of one-stop shopping: If you’re trying to practice social distancing, you likely want to consolidate your shopping into as few trips as possible. For many people, that means skipping so-called fill-in trips and buying things at a supermarket or big-box store that they might previously have bought elsewhere. Jim Hertel, a grocery industry consultant with Inmar Intelligence, says that items frequently purchased at drug stores – over-the-counter medication, for example, or cosmetics – are often getting tacked on to big grocery orders. Retailers and manufacturers may not yet have caught up to this change in behavior, leaving that type of product out of stock in certain locations. 

New consumer habits: Stay-at-home orders and the related economic fallout have scrambled purchasing decisions in various small ways that add up to big change for food retailers. Maybe you’ve taken up baking your own bread to kill time. Maybe you used to eat kale salads for lunch and now you’re scarfing comfort food like Kraft Macaroni & Cheese because it keeps in your cupboard forever and you don’t want to set foot in a store. Maybe you lost your job and have switched to cheaper brands to save money. All of this makes the work of a grocery merchandiser exceedingly difficult, and they might not always get their ordering decisions right, especially not in the short term. Over time, the food industry is going to need to figure out which of these changes are a fad and which are here to stay. For example, David Portalatin, a food industry analyst with NPD, expects pandemic shopping patterns to stoke lasting demand for frozen meals and foods, which are consistent with the recent preference for simple ingredients but offer convenience and can be stored for a long time. 

Sourcing issues: Covid-19 has ripped through U.S. meat processing plants, which temporarily shut down some production lines and contributed to shortages of meat on store shelves. Recent outbreaks at some U.S. farms raise concerns that certain produce items could end up being in short supply at various times, too. Fortunately, it’s unlikely similar issues will affect in-stock levels of many types of packaged food. Experts I spoke with said food manufacturing such as filling soda bottles is so highly automated and thus requires so few people that it’s not difficult to keep those production lines going while adhering to social distancing measures. 

Out-of-stock situations are a frustrating experience and represent a lost sale, so the industry has strong incentive to fix these problems quickly. Some of the largest players – Walmart Inc., Target Corp. and Kroger Co. – may have the easiest time doing so, as their scale gives them particular power with suppliers. Walmart and Target have the added benefit of being havens for customers who have a one-stop shopping mentality, which may only further strengthen the big-box players’ market share in the Covid-19 era. For shoppers, it’s good to know these disruptions aren’t likely to be too long-lasting. But for stores big and small, it means making the necessary adjustments before rivals do. 

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

Sarah Halzack is a Bloomberg Opinion columnist covering the consumer and retail industries. She was previously a national retail reporter for the Washington Post.

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