It costs almost twice as much to live in New York City as it does in Marshall County, Mississippi, according to figures published Wednesday by the Economic Policy Institute, a Washington think tank.

The median cost of modest living for an American family of four in the United States can be found in Newaygo County, Michigan, where $63,000 covers food, transportation, housing, child care, healthcare and taxes - but no extras such as vacations, eating out, or savings.

In New York the same lifestyle costs $93,500 and in Mississippi it can be had for $48,000.

"It's surprising to a lot of people just how much it costs to live," said Elise Gould, one of the researchers who compiled data for the policy group. EPI used data from 615 communities to update its online budget calculator (www.epi.org/resources/budget/)

Most of the household budgets identified by the EPI far exceed the 2013 official poverty line of about $23,500 for a family of four, though by varying amounts.

"There is an acknowledgement that the official poverty measure is inadequate," said Gould.

Many government benefit programs, including subsidies in the new healthcare law, are pegged to the poverty line, which is the same in all states except Alaska and Hawaii, even though regional differences in living expenses vary wildly.

The Census Bureau issued a Supplemental Poverty Measure in 2011 that varied geographically by housing costs, but many government welfare policies are still based on the official threshold.

HOUSING IS KEY

Housing costs - which can eat up as much as 25 percent of the family budget in places like San Francisco - drive the discrepancy between regions.

"Housing cost has taken up an increasing share of budgets" in recent decades said Gould, the report's chief author.

The cities with the highest total living expenses are not surprising: New York, Washington, D.C. ($88,600), Boston ($85,600) and San Francisco ($84,100).

The eight lowest-cost areas for a family of four are all counties in Mississippi. Some of the larger cities with budgets just under $60,000 are Oklahoma City and Salt Lake City.

Child care costs can eat up over one third of a family's budget in some cases. A family with one child in Washington, D.C. will pay $1,300 per month on child care, almost as much as monthly rent.

A family of four could spend anywhere from 18 percent to 33 percent of their budget on health insurance, even assuming that they received employer-provided coverage, the institute said.

Gould said the lack of savings is what keeps these families out of the middle class. "To me, middle class means economic security, and there are no savings in these budgets whatsoever," she said.