An article in Manufacturing&Service Operations Management says that an increase in the number of stores directly decreases consumer waste. The reason is improved access to groceries which would men better distribution of inventory and price competition. 

Food waste is a big problem in all developed countries; Europe became a joke in the previous decade when they set out to ban sales of 'ugly' food. In the U.S., the Department of Agriculture estimates food waste at between 30-40 percent of the food supply.

The study by Elena Belavina, Ph.D., a humanities scholar at Cornell University examined grocery industry, economic, and demographic data, finding that store density in most American cities is well below the optimal level, and modest increases in store density substantially reduces waste.

The research finds that areas like Manhattan have a lot of grocery store options and a lot of people. That reduces food waste by consumers and retailers. With more stores, households have to travel less to visit a store, which means consumers make more frequent trips with smaller purchases per trip. In turn, these smaller basket sizes imply less food waste because it's less likely the food will expire before it's used.

Thus, increasing grocery store density allows households more flexibility to decide how often and how many groceries to purchase to accommodate their needs. The author found that in a city like Chicago, results show even modest increases in store density can lead to substantial decreases in food waste.

"Just 3-4 more stores in the Chicago area can lead to 6-9% reduction in waste. This is accompanied by a 1-4% decrease in grocery expenses for households," said Belavina, an associate professor at Cornell. "What's more, increasing the number of grocery stores in a given area also works to combat emissions, while reducing consumer food expenditures, achieving two goals that are often considered competing.

"The key is finding the right number of stores for each area. An increase in the number of stores decreases consumer waste due to improved access to groceries, but too many store options increase retail waste due to relocating inventory, price competition and diminished demand by customers."