The economic literature shows that the profession understands that ‘publicness’ (non-rivalness, non-excludability) exists, and that therefore the market will ‘underprovide’. This is true even if one does not believe in the ability to properly make interpersonal comparisons of utility (which precludes summations and so forth: the inability to ‘do’ interpersonal comparisons does not mean that utility-interdependence does not exist). 

A far simpler – and far more correct – point, is that EVEN IF one accepts public-goods arguments, and EVEN IF one accepts that some omniscient State was capable of establishing precisely the extent to which these failed markets underprovide and can correct them at zero additional cost… and EVEN IF one accepts that diminishing marginal utility of money implies that ‘optimal’ taxation will take more from those with more income or wealth… it’s still WRONG to coerce.

So right off the bat, it is right to oppose the state EVEN IF government could do the minimalist, minarchist, utilitarian Rawlsian ‘thang’… leaving aside that the establishment of a bureaucracy will lead to burgeoning bloat that overexpands – and you can say that a fortiori, based on nothing more than understanding how people respond to incentives… and leaving aside that putting out big pots of money and power attracts those who should least have access to it (again, that’s a fortiori: practically axiomatic)… and leaving aside that in the final summation, all the “welfare triangles” added by government intervention come at higher cost than is ever claimed (by dint of their effects on the SUPPLY functions for ALL OTHER GOODS due to increased competition for resources in factor markets)… and leaving aside the consumer surplus that is blown to bits when States ‘do’ WAR (and ONLY States do large-scale industrial war – each costing tens of trillions of person-hours).

Our movement suffers when people say things that are economically ignorant: public goods, externalities and other forms of market failure DO exist, and it simply looks stupid to claim otherwise. 

A far better point is that trying to use a coercive State to ameliorate public goods problems, is like trying to cure the flu by giving oneself typhoid: not only will a coercive state fail to perform the function of amelioration of publicness problems, but it will introduce dynamics that will be welfare-destroying. It will attract the wrong sort of people, it will cost more than it says on the tin, it will fail to perform, it will be suborned, and it will grow faster than the rest of the economy.

And it will do so by taking money, by force or the threat of force, from those who do not wish to participate in its programs. That – slavery (or forced labour) – is the key issue. That is where the meat is – not idiotic attempts to wish publicness out of existence. Publicness exists, and we need to simply get over it, rather than trying to fix it using things that will not work, and that are funded by slavery.