One in four counties in the U.S. are ”dying” – meaning, they are recording more deaths than births – according to findings by the U.S. Census Bureau.

Demographers call this phenomenon a “natural decrease.”

The data shows that 760 of the nation’s 3,142 counties are in this category – exacerbated, analysts say, by an aging population the mortgage crisis, record high unemployment in many states and the ever-fragile economy.

These counties exist in all parts of the country, from the old Rust Belt areas of Pennsylvania and Ohio, to rural East Texas and even in the wine country of northern California.

West Virginia is the first state to experience this “natural decrease” statewide over the last decade. Maine, Pennsylvania and Vermont may soon be next, the Census data suggested.

Natural decrease is an important but not widely appreciated demographic phenomenon that is reshaping our communities in both rural and urban cores of large metro areas, said Kenneth Johnson, a sociology professor and demographer at the University of New Hampshire's Carsey Institute.

Such areas typically have aging white people who are not having children, as well as grim job prospects that drive younger adults away. These locales also tend to have few Hispanic immigrants, who, on the whole, are younger and have more children.

Indeed, the population of the entire U.S. grew by only 9.7 percent since 2000, the lowest such decade-rate since the Great Depression.

The downturn in the U.S. economy is only exacerbating the problem, said Johnson. In some cases, the only thing that can pull an area out is an influx of young Hispanic immigrants or new economic development.

The housing market is creating a new type of ghost cities in the U.S., James Follain, senior fellow and economist at the Nelson A. Rockefeller Institute of Government at the University of Albany, told the press, resulting in overbuilt urban areas suffering from huge foreclosures.

It's going to be a very slow recovery, Follain said.