Prosperity will be elusive for children, according to a new report that tracks economic well-being and opportunities.

The Economic Innovation Group, a policy and advocacy organization, finds the makings for the American Dream—prospects for higher incomes and upward mobility—are at increased risk due to failures by counties to properly endow children with the hard skills (education and trade) and soft skills (communication and networking) needed to climb the earnings ladder.

Poor and wealthier communities cross each other’s strengths and weaknesses, with richer counties failing to boost economic opportunity for young people from poor backgrounds, and economically distressed counties managing to boost opportunities. The result is that more than half of all U.S. counties exert a negative impact on children’s future earnings, the analysis finds.

The biggest takeaway from the analysis is that “place matters.” This was gleaned by reviewing the percentage increase or decrease in income at the age of 26 relative to the national mean that a child can expect by spending one additional year in any given county.

EIG looked at data from the Equality of Opportunity Project to figure how the economic situation in a place today may impact the economic opportunities of its residents tomorrow. Effects include high school graduates, poverty rates, unemployment, housing vacancies, media incomes and changes in employment, among other factors.

Interestingly, “prosperous rural areas can provide a significantly greater boost to children than even prosperous urban areas, suggesting that the quintessential engine of economic mobility may not be the urban melting pots of Horatio Alger-style myth, but rather the small town communities of the Upper Midwest,” the report says. Indeed, it claims “prosperous rural areas predominantly in the Upper Midwest and Northern Plains are the country’s most powerful areas of upward mobility.”

That said, cities are more consistent places of well-being: 50 percent of large urban counties (those with more than 500,000 people) provide an income boost to poor kids, compared to only 43 percent of rural counties.

EIG found that in total, there are 420 counties out of 2,869 in the U.S, where the American Dream of prosperity and mobility is “alive and well.”

The full report can be read here.