On this page
- Why the textbook model assumes things medicine doesn't have
- Asymmetric information: the seller knows more than the buyer
- Third-party payment: the consumer isn't the payer
- Inelastic demand: you can't shop around on a stretcher
- A worked example: the three forces stacking up
- The externality everyone assumes — and mostly isn't there
- Why no system escapes this
Walk into an emergency room with chest pain and you will be treated before anyone tells you what it costs. You will not comparison-shop. You will not negotiate. You may not see a bill for weeks, and when it arrives, a number you have never agreed to — $14,000, $40,000 — will be split between you, an insurer, and possibly the government in proportions you do not control. Now imagine buying a car this way: no sticker price, an expert salesperson who also diagnoses what you need, and a third party covering 85 percent of whatever the total turns out to be. You would expect that market to behave strangely. Healthcare does.
The numbers are staggering on their own. U.S. health spending reached $5.3 trillion in 2024 — about $15,474 per person, growing 7.2 percent in a single year, faster than the broader economy (CMS National Health Expenditure Fact Sheet). That is roughly one of every six dollars the country spends — health care now absorbs a share of GDP unmatched by any other nation, a share the Bureau of Economic Analysis tracks in the national accounts. But the size of the number is not the interesting part. The interesting part is why the ordinary tools of economics — supply, demand, a price that clears the market — fail to describe how that $5.3 trillion gets allocated.
Why the textbook model assumes things medicine doesn't have
The standard supply-and-demand model rests on a few quiet assumptions: buyers know what they are buying, buyers pay for what they consume, and buyers cut back when prices rise. In most markets these hold well enough that prices coordinate millions of strangers without anyone planning the outcome — what the Library of Economics and Liberty calls the information-carrying function of prices. Healthcare violates all three assumptions at once. As Kenneth Arrow argued in the founding paper of health economics — summarized in the Concise Encyclopedia's entry on health care — the product is ill-defined, the outcome uncertain, the providers often nonprofit, and the payments made by third parties. Each deviation breaks a different gear in the machine.
Asymmetric information: the seller knows more than the buyer
In a working market, the buyer can judge quality. You can test-drive a car, read a laptop review, taste a meal. In medicine, the person who tells you what you need — the physician — is frequently the same person who profits from providing it, and you lack the training to second-guess them. An orthopedic surgeon recommends surgery; you cannot independently evaluate whether physical therapy would have worked as well. This is asymmetric information, and it inverts the usual safeguard. Normally an informed buyer disciplines sellers. Here the seller is the informed party, and the buyer must largely trust them. That is why medicine is licensed, malpractice law exists, and professional norms carry the weight they do — the market cannot police quality on its own, so other institutions try to.
Third-party payment: the consumer isn't the payer
The deeper distortion is who pays. In 2024, out-of-pocket spending was a small slice of the total; private insurance, Medicare, and Medicaid covered the bulk (CMS NHE data). When a third party pays most of the cost at the moment of consumption, the price signal that disciplines spending in every other market goes quiet. Economists call the result moral hazard — not fraud, but the rational tendency to use more of a service when its marginal cost to you has fallen toward zero. The Library of Economics and Liberty's treatment of moral hazard in health insurance puts it plainly: comprehensive coverage leads people to consume more covered care than they would if paying out of pocket, because at the point of use it feels nearly free. Multiply that across an entire population and a large share of total spending traces to the simple fact that the consumer is not the payer.
Inelastic demand: you can't shop around on a stretcher
The third break is inelastic demand — quantity demanded barely responds to price. For a heart attack, an appendicitis, a cancer diagnosis, there is no substitute and no postponing. You cannot decide the treatment is too expensive and buy a cheaper rupture. When demand does not fall as price rises, sellers face little of the pressure that ordinarily holds prices down, and the patient has almost no bargaining leverage at the exact moment they most need care. Routine, shoppable care (LASIK, cosmetic procedures, which insurance rarely covers) behaves far more like a normal market — prices there have actually fallen — which is itself evidence that it is the combination of features, not medicine as a category, that breaks the model.
A worked example: the three forces stacking up
Follow one realistic case. A 54-year-old develops abdominal pain and is admitted for emergency surgery. At every step, the three forces compound:
- Asymmetric information. She cannot evaluate whether the recommended imaging, the specialist consult, or the inpatient night are medically necessary or defensive over-provision. She defers to the providers, who also bill for each item.
- Inelastic demand. She is not going to decline the appendectomy over price. Demand here is close to perfectly inelastic — the quantity she 'buys' is fixed by the diagnosis, not the cost.
- Third-party payment. The hospital's list charge might be $48,000. Her insurer's negotiated rate is $19,000. She pays a $3,500 out-of-pocket maximum. So the price she faces — $3,500 — bears almost no relationship to the $48,000 charge or the $19,000 actually paid.
Notice what is missing: a single price doing the coordinating work. There are at least three prices (charge, negotiated rate, patient cost), none of which the patient saw before consuming, and the one she pays is capped regardless of how much care is delivered. The signal that in any other market would tell her to economize is simply absent. This is not a flaw in one hospital's billing; it is the structural consequence of stacking asymmetric information, inelasticity, and third-party payment on top of one another.
The externality everyone assumes — and mostly isn't there
A common intuition is that healthcare deserves special treatment because one person's health benefits everyone — an externality that markets underprovide. For contagious disease, that is genuinely true: vaccination and infection control protect people beyond the patient, which is why public health is a legitimate exception. But as the Library of Economics and Liberty cautions in its essay on externalities, most medical care produces no meaningful spillover. Your knee replacement, your statin, your MRI benefit you and almost no one else. The standard public-goods argument for intervention therefore applies far more narrowly than the political debate implies. The case for treating healthcare differently rests mainly on the three market failures above — information, payment structure, inelasticity — not on a broad externality that mostly does not exist.
Why no system escapes this
Here is the part most outlets skip. Every country's healthcare system is a different arrangement of who absorbs these problems — none of them solves the underlying economics. A single-payer system concentrates the third-party payer into the government, which gains bargaining power over prices but must then ration through budgets and waiting lists, because inelastic demand against a near-zero point-of-use price would otherwise be unbounded. A market-heavy system like the U.S. preserves more choice and faster access but pays the most per person on earth, partly because fragmented payers have less leverage and moral hazard runs harder. High-deductible plans try to restore the price signal by making patients pay more at the point of use — which works for shoppable care but can backfire when it deters the cheap preventive visit that would have avoided the expensive crisis. Each design picks which trade-off to live with. There is no configuration that makes asymmetric information, inelastic demand, and third-party payment disappear.
That is the real lesson for anyone trying to make sense of a medical bill or a policy fight. The reason healthcare feels irrational — the surprise charges, the prices no one can quote in advance, the spending that climbs faster than the economy — is not that the people in it are foolish. It is that the market is missing the three things a market needs to work. Understanding that will not lower your deductible. But it will tell you why the system you are arguing about behaves the way it does, and why every proposed fix is really a choice about which broken gear to compensate for.
◆ Sources
- National Health Expenditure Fact Sheet — Centers for Medicare & Medicaid Services
- National Health Expenditure Data, Historical — Centers for Medicare & Medicaid Services
- Health Care — Concise Encyclopedia of Economics, Library of Economics and Liberty
- Moral Hazard and Health Insurance — Library of Economics and Liberty
- Information and Prices — Concise Encyclopedia of Economics, Library of Economics and Liberty
- "Externalities": Handle with Great Care — Library of Economics and Liberty
- Gross Domestic Product — Bureau of Economic Analysis





