Wouldn’t it suck if you were compelled to take medicine that you don’t think is helpful? Your bone-headed neighbors could impose bad medicine on you by majority vote. If you feel you are well informed and have very good reason to believe your neighbors are advocating snake-oil, they are under no obligation to listen to your arguments. Indeed, they create an atmosphere in which it is considered “rude” to discuss your objections to compulsory medicine in polite company; some in fact create an atmosphere in which doubting compulsory blood-letting (or needle-pricking or homeopathy) leads to shrill denunciation. Voters don’t directly pick the medical regimen, but rather pick individuals who promise their own favorite folk remedies. These individuals compete for the attention of intellectually lazy voters in a WWE-style soap opera and win more on the force of personality than on the scientific merits of their medicine. This is a world where ignorant people can inject you with bad medicine against your will, and to add insult to injury you get saddled with the bill.
And by “wouldn’t it suck” I of course mean “Doesn’t it suck,” because I have actually described the world we live in. Government policy is mostly bad medicine. Many of the things government does are demonstrably ineffective or even counterproductive. But the public asks for bad medicine and mostly gets what it wants. Gun control is snake oil for the violence problem. Minimum wage laws are homeopathy for the poverty problem. Drug prohibition is acupuncture for the addiction problem. Taxes on capital are aroma therapy for the inequality “problem.” Immigration restrictions are flagellations for the unemployment problem. Keynesian “stimulus” is blood-letting for economic recessions. There is left-wing-populist snake oil and right-wing-populist snake oil, much of it overlapping.
Government policy is medicine for various social problems, and most of it doesn’t work. We can evaluate government policy the same way we evaluate medicine for effectiveness: regression analysis, time series, randomized experiment, instrumental variables, (insert your favorite statistical method here), etc. We somehow compare a “treated” to an “untreated” population, we measure the difference in outcomes, we determine how much of the difference in outcome is due to the treatment, we quantify the uncertainty in our estimate (is it “statistically significant” or not?), and we decide whether the treatment is cost-justified or not. For most of what the government does, you either can’t find any effect at all or you find the opposite of the intended effect. It’s hard to even “move the needle” in the targeted direction. For many policies, there is a small positive effect, but it is purchased at such an enormous cost that the policy can only be called a failure. For other policies, the point estimate for net benefits (total benefits – total costs) may be positive, but the uncertainty around the estimate is so huge that you have no idea whether it’s a net benefit or not. It shouldn’t be terribly controversial to call for the elimination of government programs that are “bad medicine” in one of the ways articulated above. But even if medicine is provably, uncontrovertibly effective *as well as* being cost effective, should you then be able to force it on an unwilling patient?
Most people would not hold down an unwilling victim and inject them with unwanted medicine. Even people who despise anti-vaxers mostly don’t think we should forcibly vaccinate them or even their children. Of course there are some decisions that affect the entire society and thus must be shared. We can’t all have our own “nuclear deterrence” policy, and I can’t have a different pollution standard on my plot of land than my neighbor’s plot mere feet away. Likewise there can only be one “monetary policy” governing the dollar. But I can set my own personal minimum wage, as in “I will not work for less than $X/hour.” This has the advantage that I can change my policy if I’ve made a terrible mistake of setting X too high, which would preclude my finding a job, or too low, which would leave me undercompensated for my skills and experience. I can set my own “tolerance toward immigrants” policy. If I am culturally benighted and find immigrants of certain nationalities distasteful I can mostly avoid them. I can set my own “drug prohibition” policy; perhaps my homeowners association or condo or apartment complex wishes to enforce a “no drugs” policy. That’s fine; the people who want a drug free environment can pay the costs of maintaining it. People who want drugs can use them without being beaten up, and they are spared the indignity of paying for the government policies that abuse them. Those organizations attempting to enforce local drug prohibition might be faced with the realization that enforcement is too costly and too destructive of personal privacy. This is a feature, not a bug, of having private rather than public policy. The discovery process that identifies good and bad policy is allowed to operate in the private sphere; the same discovery process either does not take place *at all* or takes place very slowly and clumsily in the public sphere.
There you have two good reasons for a presumption *against* government coercion. One is strictly moral: the thing that government does is almost universally recognized as immoral in a slightly different context. The other is practical: doing things coercively shuts off the discovery process, whereby individuals who make mistakes can adjust their behavior.