In September, two weeks before the Affordable Care Act was due to launch, President Obama declared that "there's no serious evidence that the law . . . is holding back economic growth." As for repealing ObamaCare, he added, "That's not an agenda for economic growth. You're not going to meet an economist who says that that's a number-one priority in terms of boosting growth and jobs in this country—at least not a serious economist."
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Casey Mulligan Ken Fallin
In a way, Mr. Obama had a point: "Never met him," says economist Casey Mulligan. If the unfamiliarity is mutual, the confusion is all presidential. Mr. Mulligan studies how government choices influence the incentives and rewards for work—and many more people may recognize the University of Chicago professor as a serious economist after this week. That's because, more than anyone, Mr. Mulligan is responsible for the still-raging furor over the Congressional Budget Office's conclusion that ObamaCare will, in fact, harm growth and jobs.
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Rarely are political tempers so raw over an 11-page appendix to a dense budget projection for the next decade. But then the CBO—Congress's official fiscal scorekeeper, widely revered by Democrats and Republicans alike as the gold standard of economic analysis—reported that by 2024 the equivalent of 2.5 million Americans who were otherwise willing and able to work before ObamaCare will work less or not at all as a result of ObamaCare.
As the CBO admits, that's a "substantially larger" and "considerably higher" subtraction to the labor force than the mere 800,000 the budget office estimated in 2010. The overall level of labor will fall by 1.5% to 2% over the decade, the CBO figures.
Mr. Mulligan's empirical research puts the best estimate of the contraction at 3%. The CBO still has some of the economics wrong, he said in a phone interview Thursday, "but, boy, it's a lot better to be off by a factor of two than a factor of six."
The CBO's intellectual conversion is all the more notable for accepting Mr. Mulligan's premise, which is that what economists call "implicit marginal tax rates" in ObamaCare make work less financially valuable for lower-income Americans. Because the insurance subsidies are tied to income and phase out as cash wages rise, some people will have the incentive to remain poorer in order to continue capturing higher benefits. Another way of putting it is that taking away benefits has the same effect as a direct tax, so lower-income workers are discouraged from climbing the income ladder by working harder, logging extra hours, taking a promotion or investing in their future earnings through job training or education.
The CBO works in mysterious ways, but its commentary and a footnote suggest that two National Bureau of Economic Research papers Mr. Mulligan published last August were "roughly" the most important drivers of this revision to its model. In short, the CBO has pulled this economist's arguments and analysis from the fringes to center of the health-care debate.
For his part, Mr. Mulligan declines to take too much credit. "I'm not an expert in that town, Washington," he says, "but I showed them my work and I know they listened, carefully."
At a February 2013 hearing he pointed out several discrepancies between the CBO's marginal-tax-rate work and its health-care work, and, he says, "That couldn't persist forever. There would have to be a time where they would reconcile those two approaches somehow." More to the point, "I knew eventually it would be acknowledged that when you pay people for being low income you are going to have more low-income people."
Mr. Mulligan thinks the CBO deserves particular credit for learning and then revising the old 800,000 number, not least because so many liberals cited it to dispute the claims of ObamaCare's critics. The new finding might have prompted a debate about the marginal tax rates confronting the poor, but—well, it didn't.
Instead, liberals have turned to claiming that ObamaCare's missing workers will be a gift to society. Since employers aren't cutting jobs per se through layoffs or hourly take-backs, people are merely choosing rationally to supply less labor. Thanks to ObamaCare, we're told, Americans can finally quit the salt mines and blacking factories and retire early, or spend more time with the children, or become artists.
Mr. Mulligan reserves particular scorn for the economists making this "eliminated from the drudgery of labor market" argument, which he views as a form of trahison des clercs. "I don't know what their intentions are," he says, choosing his words carefully, "but it looks like they're trying to leverage the lack of economic education in their audience by making these sorts of points."
A job, Mr. Mulligan explains, "is a transaction between buyers and sellers. When a transaction doesn't happen, it doesn't happen. We know that it doesn't matter on which side of the market you put the disincentives, the results are the same. . . . In this case you're putting an implicit tax on work for households, and employers aren't willing to compensate the households enough so they'll still work." Jobs can be destroyed by sellers (workers) as much as buyers (businesses).
He adds: "I can understand something like cigarettes and people believe that there's too much smoking, so we put a tax on cigarettes, so people smoke less, and we say that's a good thing. OK. But are we saying we were working too much before? Is that the new argument? I mean make up your mind. We've been complaining for six years now that there's not enough work being done. . . . Even before the recession there was too little work in the economy. Now all of a sudden we wake up and say we're glad that people are working less? We're pursuing our dreams?"
The larger betrayal, Mr. Mulligan argues, is that the same economists now praising the great shrinking workforce used to claim that ObamaCare would expand the labor market.
He points to a 2011 letter organized by Harvard's David Cutler and the University of Chicago's Harold Pollack, signed by dozens of left-leaning economists including Nobel laureates, stating "our strong conclusion" that ObamaCare will strengthen the economy and create 250,000 to 400,000 jobs annually. (Mr. Cutler has since qualified and walked back some of his claims.)
"Why didn't they say, no, we didn't mean the labor market's going to get bigger. We mean it's going to get smaller in a good way," Mr. Mulligan wonders. "I'm unhappy with that, to be honest, as an American, as an economist. Those kind of conclusions are tarnishing the field of economics, which is a great, maybe the greatest, field. They're sure not making it look good by doing stuff like that."
Mr. Mulligan's investigation into the Affordable Care Act builds on his earlier work studying the 2009 Recovery and Reinvestment Act, aka the stimulus.
The Keynesian economists who dominate Mr. Obama's Washington are preoccupied by demand, and their explanation for persistently high post-recession unemployment is weak demand for goods and thus demand for labor. Mr. Mulligan, by contrast, studies the supply of labor and attributes the state of the economy in large part to the expansion of the entitlement and welfare state, such as the surge in food stamps, unemployment benefits, Medicaid and other safety-net programs. As these benefits were enriched and extended to more people by the stimulus, he argues in his 2012 book "The Redistribution Recession," they were responsible for about half the drop in work hours since 2007, and possibly more.
The nearby chart tracks marginal tax rates over time for nonelderly household heads and spouses with median earnings. This index is a population-weighted average over various ages, jobs, employment decisions like full-time versus part-time. Basically, the chart shows the extra taxes paid and government benefits foregone as a result of earning an extra dollar of income.
The stimulus caused a spike in marginal rates, but at least it was temporary. ObamaCare will bring them permanently into the 47% range, or seven percentage points higher than in early 2007. Mr. Mulligan says the main response to his calculations is that people "didn't realize the cumulative effect of these things together as a package to discourage work."
Mr. Mulligan is uncomfortable speculating about whether the benefits of this shift outweigh the costs. Perhaps the public was willing to trade market efficiency for more income security after the 2008 crisis. "As an economist I can't argue with that," he says. "The thing that I argue with is the denial that there is a trade-off. I argue with the denial that if you pay unemployed people you're going to get more unemployed people. There are consequences of that. That doesn't mean the consequences aren't worth paying. But you can't deny the consequences for the labor market."
One major risk is slower economic growth over time as people leave the workforce and contribute less to national prosperity. Another is that social programs with high marginal rates end up perpetuating the problems they're supposed to be alleviating.
So amid the current wave of liberal ObamaCare denial about these realities, how did Mr. Mulligan end up conducting such "unconventional" research?
"Unconventional?" he asks with more than a little disbelief. "It's not unconventional at all. The critique I get is that it's not complicated enough."
Well, then how come the CBO's adoption of his insights is causing such a ruckus?
"I would phrase the question a little differently," Mr. Mulligan responds, "which is: Why didn't conventional economic analysis make its way to Washington? Why was I the only delivery boy? Why wasn't there a laundry list?" The charitable explanation, he says, is that there was "a general lack of awareness" and economists simply didn't realize everything that government was doing to undermine incentives for work. "You have to dig into it and see it," he explains. "The Affordable Care Act's not going to come and shake you out of your bed and say, 'Look what's in me.' "
Judging by their reaction to the CBO report, the less charitable explanation is that liberals would have preferred that the public never found out.
Mr. Rago is a member of the Journal's editorial board.