Final answer:
The concern is that an aging population will lead to a decreased labor force participation rate in the United States and lower tax revenues.
Step-by-step explanation:
One concern among economists regarding the aging of the U.S. population is that since older people are less likely to work, it will lead to a decreased labor force participation rate in the United States and lower tax revenues.
As a result, an aging population will have a negative impact on the economy.
Therefore, the correct option is: Since older people are less likely to work, an aging population will lead to a decreased labor force participation rate in the United States and lower tax revenues.
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