If Governments price carbon then the cost of supplying meat will increase and market quantities will fall (all else equal). Your prediction that meat would become more of an exclusive meal item assumes that none of the factors influencing demand have changed, so people can’t afford to eat meat as much anymore.

However, there are some significant demand factors that make the quantity effect of an increase in the cost of supplying meat ambiguous at best. I am thinking of demographic changes influencing the demand for meat over the next 20 years, like changing attitudes in India towards eating beef and the effect of rising income levels in the developing world.

Maybe Stern is hoping that he can convince the developed world to go vegan, so their demand for meat is just replaced rather than compounded? He obviously hasn’t learned yet that the developing world isn’t listening to him.

One interpretation is that we have a strategy choice between persuading people to vote for change and persuading them to implement change. In theory we can do both, but I think only the former can succeed and both are currently failing. The climate change vote seems to be small and limited to people swinging between green and left, so is electorally irrelevant in most countries, even those with some form of proportional voting.

“In addition, it is pretty obvious that price is only one determinant of people’s behaviour. Therefor attitudes are not irrelevant.”

Attitudes are just short-hand for preferences that are (partially) socially determined. People should be allowed to hold these preferences, but should have to pay the full cost for the actions they take on. When we have a policy goal we solely want to make it such that people face the full costs of their actions.

In this sense the attitude is irrelevant UNLESS we feel that the value of the outcomes that would occur with different attitudes (which can be adjusted because they are partially socially determined, but are costly to adjust) is sufficiently better. This is a claim I would be uncomfortable making.

On point 3 I agree – but in this case it seems more likely that in practice we could achieve the first best outcome (one where we accurately price carbon) than some second-best outcome where we guilt people into changing consumption habits. As a result, I don’t see a practical policy trade-off between these methods here.

In addition, it is pretty obvious that price is only one determinant of people’s behaviour. Therefor attitudes are not irrelevant.

Thirdly, accurately pricing carbon is just about impossible, given the uncertainties. Governments either set a tax level, or a cap on emissions. Where this is set is at best a guestimate, and may not properly represent the full externalities. Much pricing of natural resources, in fact, is based on little more than people’s willingness to pay.

So in principle, yes, but in practise not likely

I think his point on attitudes is irrelevant – even if I can conceive of that actually happening. It is like an argument where the premises are true, but the conclusion doesn’t actually logically follow from them.