[Naed_force]

The government can charge rent for utilisation of land and other natural resources. That's not the same thing as a tax, and it can be morally justified.

Revenue from such rent would be enough to cover the government dealing with externalities, whether that be generating positive externalities or reducing negative ones.

Welfare is a nonvoluntary transfer of income, to force one party to provide for the basic needs of another. It can't happen in a free society. It leads to an explosion in single parenthood. When a guaranteed income is conditioned only on a person existing, then you will encourage people to bring people into existence at the lowest possible cost to themselves. That's indeed what the statistics show for Western countries over the last 40 years.

[maxander]

The birth rates in Western countries have been plummeting for the last 40 years. In fact, birth rates globally are declining almost everywhere except in countries that are still too poor to provide things like welfare. The data does not support your position.

[Jabanga]

The rate of single parenthood (particularly low income single parenthood) has been exploding in the West, concurrent with rising social welfare spending.

As for the general birthrate, that seems to be affected by income, not the availability of welfare. This is indicated by examples like Hong Kong and Singapore, which have much lower levels of welfare than most developed countries, and much lower birthrates.