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Wal-Mart Stores Inc. (NYSE: WMT) sales are heavily concentrated in only about half the states in the U.S. To a lesser extent, Macy’s Inc.’s (NYSE: M) are as well. As retailers reported less than rosy forecasts and disappointing results, markets panicked and sold down shares in each one.

Retail sales are like most other economic activity — uneven from state to state and city to city. Yet, major retailers do not break out local figures, which might, in turn, calm investors who could see that problems stem primarily from one region or two.

Walmart does provide total U.S. sales, though that is only of modest help to Wall Street. The improvement at Walmart U.S. was worse than that of Sam’s Club or Walmart International. Revenue at the company’s biggest unit was only up 2.1% to $68.7 billion during the most recently reported quarter. The growth for the past six months was even less inspiring.

As for Walmart’s guidance, sales by region were not offered at all.

Macy’s has no large international division to offset U.S. sales when activity outside American outstrips that inside. Like Walmart, Macy’s reported nothing about sales by state or region. Similarly, Macy’s modest forecast, which caused so much consternation, mentioned nothing about where the firm’s severest trouble might be. This was all that Macy’s reported about local activity:

In the second quarter, the company opened a new Macy’s store in Gurnee, IL, and a Bloomingdale’s Outlet store in Rosemont, IL. A Macy’s store was closed in St. Louis, MO. In the second half of 2013, the company is opening a new Bloomingdale’s store in Glendale, CA, and a new Macy’s replacement store in Bay Shore, NY, as previously announced.

The differences from place to place can have a profound effect on revenue and profits. Part of this is due to demographics, and sometimes weather, and less frequently to gasoline prices. In theory, areas in which median income is low may be hurt because factors in the economy usually take discretionary income from them first. Walmart is particularly susceptible to this because so many of its shoppers have modest incomes, and often very low ones.

Macy’s and Walmart know, store by store, how they did last quarter and how they are likely to do this one. Between Macy’s flagship brand and its Bloomingdale’s operation, it has nearly 900 locations. Walmart has more than 4,700 outlets in the United States. Not a single sentence in the financial results of either company indicates how well or how poorly any of these locations have done.