If not for job lock, we’d probably see greater job mobility and entrepreneurship. According to one analysis, two million more people would change jobs if it weren’t for job lock — presumably finding work that makes them happier or that is better suited for them. One study found that 25-to-55-year-old married men with no other coverage options are 22.5 percent less likely to switch jobs compared with those who have alternatives. Another study, examining 24-to-35-year-old married men, estimated smaller effects, between 10 and 15 percent.

The evidence of sticking with jobs instead of starting a business is mixed, but the preponderance of it suggests this kind of “entrepreneurship lock” exists, affecting up to four million people. Workers without coverage from a spouse — therefore, more reliant on their own employers’ coverage — are a few percentage points less likely to become self-employed, according to one study. Similarly, self-employment spikes when workers turn 65 and obtain Medicare coverage.

From the late 1980s to the early 2000s, tax deductibility of policies for self-employed workers was phased in, making those policies more affordable. Two studies provide evidence that this change increased self-employment. One found that it rose 10 percent among women without health coverage from a spouse versus those with such coverage. Another found that the tax change explained as much as half the total increase in self-employment between 1999 and 2004.

All of these studies suggest that job lock would be alleviated by more available and affordable coverage outside work. Whether Obamacare did that is less clear. Many policy experts expected the A.C.A. to reduce job lock. An analysis by the Urban Institute, conducted before the health insurance reforms were implemented, estimated that the self-employed would increase by about 1.5 million individuals as a result of the law. In 2014, the Congressional Budget Office anticipated that the A.C.A. would reduce the size of the labor force by at least two million people by 2024.

One post-A.C.A. study found that the prohibition of pre-existing condition exclusions for children increased job mobility for their parents. And in the months after the insurance market reforms rolled out, voluntary part-time work increased and the growth in the number of workers over age 55 slowed, both consistent with alleviation of job lock. But more rigorous studies of part-time work did not find an impact from the A.C.A.

According to a review of scientific papers by the economists Jean Abraham and Anne Royalty, for the University of Pennsylvania’s Leonard Davis Institute of Health Economics, few other studies have found solid evidence that the A.C.A. reduced job lock or had other effects on the labor market. For instance, studies have not found that allowing children to stay on their parents’ insurance until age 26 has influenced the labor market choices of young adults. Nor have they found that the A.C.A. increased early retirement or employment more generally.

One reason studies might not have found an impact on job lock could be because the law is relatively new, and there isn’t enough data available to researchers to tease out all its effects. It could also be because the law has been under siege on multiple fronts since passage, rendering its status uncertain. This may have raised doubts in workers’ minds about the wisdom of relying on it as a substitute for employer-offered coverage.

But it is clear that with A.C.A. repeal on the table, people contemplating early retirement may need to reconsider.