Opinion | How Joe Biden Can Own Health Care

The bottom line is that Mr. Biden’s plan would not achieve universal insurance and would leave many with private insurance continuing to face high costs. Yes, his plan also has a relatively modest 10-year cost. But, partly for that reason, it would expand the reach of federal insurance only modestly, which means in turn it would be unlikely to rein in prices on its own.

Ms. Warren’s public option is very different. It would offer broader benefits on more generous terms than any existing proposal besides Mr. Sanders’s, including free coverage for everyone under age 18. Her public option would automatically enroll everyone younger than 50 who lacked alternative coverage. Those over age 50 would be able to enroll directly in Medicare — that is, a full decade before they could join Medicare under Mr. Biden’s current proposal.

Ms. Warren’s plan also includes a number of specific measures to reduce the prices paid by the federal government. Moreover, her public option is so generous, it’s certain to get substantial enrollment, so that pricing power will reach a big and growing share of the market.

Indeed, Ms. Warren’s public option is so generous that if it were set up, tens of millions of insured Americans with workplace coverage would likely jump into it. (Mr. Biden also allows those with employer-sponsored insurance to enroll in the public option, but his public option is much less attractive.) Based on an independent analysis of a similar plan I developed roughly a decade ago, I estimate that 50 million Americans would immediately enroll, with the number rising over time.

The big challenge with Ms. Warren’s proposal is that it also would involve much more new tax financing than Mr. Biden’s. Still, there’s ample ground between the two approaches for a broader, better public option than Mr. Biden’s. It wouldn’t be hard to add stronger measures to enroll people who lack alternative coverage — to make the public option essentially a default source of coverage for everyone without private workplace plans. Nor would be it be hard to make sure that these private plans meet high (and rising) standards. And Mr. Biden’s public option would have more long-term potential if he committed himself to beefing up the federal government’s pricing power while making his promised benefits more generous.

Whether or not these steps would be good for his candidacy, they would be good for Americans who desperately want to know they’ll have quality coverage not tied to a specific job that won’t keep piling health care costs onto them.

Jacob S. Hacker, a professor of political science at Yale, is the author of “The Great Risk Shift: The New Economic Insecurity and the Decline of the American Dream” and, with Paul Pierson, the forthcoming “Let Them Eat Tweets: How the Right Rules in an Age of Extreme Inequality.”

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