New York (CNN Business) America's population is aging and Millennials are having fewer kids than older generations did. That's a risk to the US economy that is not receiving as much attention as concerns about interest rates, the trade war and corporate earnings.

The longer-term risk of slowing population growth "poses particular economic challenges," said David Kelly, chief global strategist with JPMorgan Funds, in a recent report. He is concerned policymakers are not addressing the issue, which could hurt the market, especially if some of President Trump's proposed plans for "merit-based immigration" and increased border security are enacted.

Kelly will talk about this, as well as other factors affecting the markets and global economy, with CNN Business editor-at-large Richard Quest on the "Markets Now" live show Wednesday at 12:45 pm ET.

Kelly said that the combination of retiring boomers and a shortage of working-age Americans creates a problem that "is particularly awkward for the economy." He added that this trend should "persist throughout the 2020s."

That's why Kelly advises that the United States "should probably be having a serious conversation about temporarily boosting, rather than reducing, immigration, at least while the baby boom is retiring."

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