Can America afford to become a major social welfare state?

Mr. Okun explains the trade-off with a metaphor: Providing a social safety net is like using a leaky bucket to redistribute water among people with different amounts. While bringing water to the thirstiest may be noble, it is also costly as some water is lost in transit.

In the real world, this leakage occurs because higher taxes distort incentives and impede economic growth. And those taxes aren’t just the explicit ones that finance benefits such as public education or health care. They also include implicit taxes baked into the benefits themselves. If these benefits decline when your income rises, people are discouraged from working. This implicit tax distorts incentives just as explicit taxes do. That doesn’t mean there is no point in trying to help those in need, but it does require being mindful of the downsides of doing so.

Which brings us back to Western Europe. Compared with the United States, G.D.P. per person in 2019 was 14 percent lower in Germany, 24 percent lower in France and 26 percent lower in the United Kingdom.

Economists disagree about why European nations are less prosperous than the United States. But a leading hypothesis, advanced by Edward Prescott, a Nobel laureate, in 2003, is that Europeans work less than Americans because they face higher taxes to finance a more generous social safety net.