For public goods, is it right to say that they are underproduced because producers find it difficult to exclude non-payers? Or is that not one of the points i should've written? If so, how many marks would that cost me in a 12 mark essay? I also forgot to mention the 'free-rider' problem but said something about non-payers.
I mentioned the non-rivalry and non-excludability factors and generally said that National Defense was better than Public Parks in terms of priority of the government and an example of a public good.
Is that remotely right?