With enrollment for ObamaCare beginning today, Reason lists eight potential problems with ObamaCare, including …

1) When more people have health insurance, it could be harder to see primary care physicians: There’s already a shortage of primary care physicians relative to national demand. Increasing the number of people who have health insurance tends to increase the demand for physicians’ services. As the Associated Press reported this week, “A shortage of primary care physicians in some parts of the country is expected to worsen as millions of newly insured Americans gain coverage under the federal health care law next year. Doctors could face a backlog, and patients could find it difficult to get quick appointments.”

2) Health insurers will limit doctor networks in order to keep prices down: When California’s insurance regulators first released information on health premiums through the state’s insurance exchange, they touted lower than expected rates. But the comparison was misleading, stacking the exchange’s individual premiums up against small business rates. And there was something else they didn’t say either: Many of the state’s health insurers held down prices by strictly limiting the available providers. “To hold down premiums,” the L.A. Times reported this week, “major insurers in California have sharply limited the number of doctors and hospitals available to patients in the state’s new health insurance market opening Oct. 1.”

3) Employers will cut hours for workers. Jed Graham of Investor’s Business Daily has put together a list of more than 300 employers who have already reduced hours or full-time employment in order to avoid potential requirements under Obamacare. Labor leader Richard Trumka, who supported the law, has said that employers are now cutting hours to avoid the law’s mandates. And this is with the employer mandate delayed for a year.  …

5) The online exchange technology won’t be ready — or won’t work as well as its supposed to. The state of Oregon, one of the states that has been most enthusiastic about implementing the law, has already said that online enrollment will not be available on October 1. Health officials working on the law, meanwhile, have begun to view the beginning of enrollment in October as a “soft launch,” according to The Washington Post. And independent health care investment analysts are warning that when the exchanges are launched that “technical glitches and functional issues” are “probable.”

6) Employers could move many more workers than expected onto the exchanges, and increase the price of the law as a result. Small changes in household premium contributions for workers in employer sponsored insurance could make the exchanges much more attractive to millions of people, according to a recent study in Health Affairs. “As household premium contributions rise,” the study explains, “people are increasingly eligible and motivated to participate in the exchange, because they will receive a federal premium subsidy and an effective wage increase (to compensate for leaving employer-provided insurance).” Adjusting the average national premium contribution by just $100 could push 2.2 million people to move into the exchange, the study warns, and, thanks to greater reliance on public subsidies for coverage, increase the law’s federal price tag by $6.7 billion.

Contrary to what ObamaCare cheerleader U.S. Rep. Ron Kind (D–La Crosse) claims, number three is already happening. You’d think Kind would be embarrassed to find out, at a forum he sponsored to cheerlead for ObamaCare, that at least two major employers in the southern part of his Third Congressional District cut employee hours months before ObamaCare became law. Number six is already happening now as well, because health insurance has been increasing in cost far faster than ObamaCare’s cheerleaders thought. Oops.

Bloomberg adds 11 bits of conventional ObamaCare wisdom about which you should think otherwise, including …

1. Once Obamacare goes into effect, it will be impossible to substantially cut it back. Both sides seem convinced of this — Republicans in terror, Democrats in glee. Funny thing, though — the other day, my father mentioned casually that many of his classmates at the Syracuse’s Maxwell School of Public Policy in the mid-to-late 1960s had been on Medicaid. And then, suddenly, they weren’t.

It turns out that in 1965, when Medicaid passed, the State of New York had a great idea: shower a bounty of federal money on New Yorkers by setting the income eligibility limits much higher than other states. They financed this by requiring the local government to kick in 25 percent of the cost. The Feds matched state + local dollars, so that for each dollar New York State spent, it got one local and two federal dollars to go along with it. At the income levels they set, a third of the state was eligible.

Then, the Federal government noticed that it was spending many multiples of what had been projected, with a lot of those dollars going to New York. New York cut back the program sharply, turning Medicaid into what it is today — a shoestring program for low-income families, rather than the comprehensive middle-income safety net that New York State had envisioned.

This drama has played out in other states, most recently in Tennessee, where a large Medicaid expansion into more middle-class populations had to be rolled back when the state could no longer fund it. Entitlements are hard to roll back, but it is clearly not impossible, because it’s been done.

2. Accountable Care Organizations are certain to bring down overall health spending . Here’s another interesting observation I heard the other day, this time from a participant in the recent Brookings’ papers: it’s not clear that ACOs are going to save money. The idea behind ACOs is that they will help us move away from fee-for-service medicine, in which doctors are paid for doing stuff, and toward a system where doctors are paid by the patient, a system usually rendered in the popular lexicon as “paying for health, not treatment.” The unspoken underlying assumption being that this means “paying less for health.”

This is the holy grail of health care economists, and perhaps it is finally upon us. But we should be cautious. The obvious reason is that “health” is hard to measure, so what you often end up is “paying for the condition of the patient.” That is, you give doctors a certain fee for all patients with moderate heart disease, diabetes and a thyroid condition. Since they get the same fee no matter what they do, you end the incentives for overtreatment. Cynics have observed, however, that you then create incentives for undertreatment. The cynics are right.

The un-obvious reason that we shouldn’t be too confident in the ACO revolution is that bundling payments this way encourages — in fact, nearly requires — doctors to band together in much larger practice groups. A small practitioner with a few hundred patients is extremely vulnerable to the possibility that some of those patients will end up requiring much more treatment than their health status classification would predict. A few of those, and you’ve lost money for the year. And what if those patients are also extra-expensive next year? Bankruptcy court looms. So you need a very large practice to make the financials work, so that you can be sure that the extra-expensive patients are balanced out by some extra-cheap ones. This also makes it easier to manage a patient’s entire set of health problems within a single practice.

But as the participant pointed out, consolidation is one of the things that is known to drive up prices in health care markets. When you’re an insurer negotiating with 2,500 individual doctors, you have a fair amount of leverage to keep their fees down. When you’re negotiating with four large practice groups, suddenly you’re not so powerful, because you might lose customers if your policy excludes a quarter of the doctors in town. So it’s not yet clear whether ACOs are actually going to lower costs — or even work at all. …

6. Breaking the link between health insurance and employment will spur entrepreneurship. There’s a decent amount of evidence suggesting that access to health insurance outside of your job reduces what economists call “job lock” — people who stay tied to a job when they’d rather be elsewhere. This has led a lot of observers suggest that we might be on the verge of turbocharging our economy by unleashing a wave of entrepreneurs who are currently tied to their job for the insurance.

It’s a compelling, and entirely plausible, story. But at this point, it’s just a story. For a lengthy discussion of the various studies, and why we might or might not believe them, you can read the piece I wrote this summer. The TL;DR version is that people who have a chronic illness end up tied to their jobs for lots of reasons — you don’t want to take many risks if you, or a loved one, might have a medical emergency at any moment, so it’s not clear how much health insurance, rather than the steady paycheck, accounts for the job lock. And while ending job lock may unleash entrepreneurship, it may also encourage people to exit the labor force earlier than they otherwise would, creating a net drag on the economy.

You also have to consider the fact that the new health care law raises the cost of expanding your company — suddenly, when you hit that 50th employee, you either have to buy them all health insurance, or pay a big penalty. (At least, assuming the employer mandate actually eventually takes effect.) On the other hand, it might lower the costs of growing a small company, since you don’t have to buy your employees health insurance to tempt them away from a larger company. It’s all very complicated. Which is why this should be classified as “speculative” rather than “conventional wisdom.” …

9. People with pre-existing conditions will be able to buy insurance in the private market for the first time. I used to believe that I was uninsurable in the private market, because I have a (fairly boring) autoimmune disease. My colleague Virginia Postrel, a breast cancer survivor who buys insurance in the private market, set me straight. Since the Health Insurance Portability and Accountability Act passed in 1996, people with pre-existing conditions can still be covered as long as they maintain health coverage. It’s only if your coverage lapses that you run into trouble.

Obviously, not everyone maintains coverage — when you’ve lost a job, health insurance is often one of the first things that gets cut, and some people never had coverage in the first place. But it isn’t true that no one with pre-existing conditions could get health insurance before Obamacare came along and fixed everything.

This is, by the way, one more reason to be skeptical of predictions that we’re about to unlock a massive untapped well of entrepreneurship.

“Skeptical”? I’m not skeptical at all. It is absolutely ludicrous to assume that ObamaCare is going to “unlock a massive untapped well” of anything except ObamaCare disaster stories.