"It's a demographic gridlock," Yardeni said in a phone interview. Boomers will not want to give up their long-awaited benefits. Nor will working-age singles—burdened with record-level student debt—welcome tax hikes.
Incentives for young singles to pay into these retirement programs are low. With older generations drying up the coffers, singles expect little-to-no economic return. "It's dead weight loss. A burden," Yardeni said.
One solution is to welcome more young, tax paying immigrants into the country, Yardeni suggested.
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Minorities have higher birth rates and can prevent an inverted population pyramid, a phenomenon in rapidly aging countries like Japan, where there are more old people than young. Counting on immigrants is unrealistic, he said, until Congress can reach consensus on reform.
Singles and the safety net
Although the singles majority jeopardizes retirement programs' funds, they may have the opposite effect on welfare programs for the poor, said Robert Moffitt, a Johns Hopkins University economist who specializes in safety nets.
Spending on assistance for the poor will go down if the singles majority persists, he said, since most welfare programs are heavily biased toward providing benefits to families with kids.
"If you're a childless single and healthy, then you're on your own and won't qualify for most safety net programs," he said in a phone interview.
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Unless eligibility rules for entitlement programs change, more singles without families and kids mean fewer adults will be able to receive welfare benefits.
One exception: If a majority of singles is poor, food stamps may see an increase in expenditure since it is the one program that all adults can qualify for regardless of children.
"You get an average of $5 a day for food stamps. That's all you're qualified to get if you're a poor, unemployed single," Moffitt said.