Question

Why can requiring payment for use of public services and goods prevent a tragedy of the commons?

Answer 1

Requiring payment for use of public services and goods should reduce the over usage of common (i.e. public) services/goods.

Explanation:

The "tragedy of the commons" originally referred to the over use of public lands (for grazing). It cost farmers nothing to allow their animals to graze on the public (common) tracts of land and this enabled them to individually increase their profit margin. However since everyone did this, the quality of the commons became degraded to the point that it was useless for everyone.

By charging for the use of common goods/services, the profit advantage of using such services is reduced and there will be less incentive to use "the commons" (and thus reduced usage with the possible prevention of over usage).