The wholesale price of eggs has dropped sharply since the beginning of March after soaring for months, but it may take a few weeks for grocery shoppers to see the decline.

Wholesale egg prices, which is what retailers pay to procure eggs, have fallen to a national average of just over $4 for a dozen large white eggs, down from a peak of more than $8 at the end of February, according to data from the Agriculture Department released last week.

But because eggs typically have a four-week shelf life, it may be the end of March before retail prices start to drop, said Jeremy Horpedahl, an associate professor of economics at University of Central Arkansas. Some stores, he added, may not lower prices until their current inventory sells out.

Economists said that the decline in wholesale prices, which are still above long-term averages, was very likely fueled by a combination of factors: bird flu coming under control, weaker consumer demand, ramped-up supply and producer pricing decisions. The Agriculture Department noted that there had been no significant outbreaks of avian flu in March so far, and economists say any new outbreaks could push up prices again. The virus has forced egg producers to cull tens of millions of hens since late last year.

In February, the retail price of eggs rose 10.4 percent from the previous month, continuing a monthslong climb, according to data from the Bureau of Labor Statistics released last week.

Economists noted that prices might not come down evenly across the country. Areas with competing grocery stores might see egg prices fall more quickly, Mr. Horpedahl said, while those dominated by a single chain — with the power to keep prices high for longer — may not. Retail prices may also depend on grocery chains’ strategies, with some opting to keep prices lower to entice customers into stores.