Katare et al. (2020) on Optimal Meat Consumption

 Bhagyashree Katare, H. Holly Wang, Jonathan Lawing, Na Hao, Timothy Park, and Michael Wetzstein, "Toward Optimal Meat Consumption." American Journal of Agricultural Economics 102(2): 662-680, March 2020.

Meat consumption worldwide increased by more that a factor of five between 1992 and 2016, with concomitant negative effects on the environment and health. Many of these harms are of the external variety, and thus present the usual case for potentially welfare-improving policy interventions -- including a Pigovian meat tax. But the existence of external costs does not in itself establish the optimality of a Pigovian tax; perhaps improved consumer information or a campaign aimed at voluntary reductions in meat consumption would be preferable policy responses. Alternatively, changes in production methods could reduce the environmental impact of the meat industry.

The authors compare a meat tax with a mandatory labelling scheme, where the labels on meat products would indicate the environmental and health costs of meat production and consumption. The authors note that individuals enjoy behaving in what they see as a prosocial manner, providing an intrinsic motivation to reduce meat consumption. This intrinsic motivation, they argue, can be counteracted by the presence of external motivations to reduce meat consumption, via a meat tax, for instance -- this type of crowding out has been examined pretty broadly within behavioral economics. Green labelling (as opposed to the tax) could promote, not undermine, intrinsic incentives to reduce meat consumption. (Although the opposite effect, that being constantly lectured to cut back on meat could incentivize more meat consumption, seems possible, too.) Other issues to consider are the potential that the substitutes to meat consumption might involve external social costs of their own, and the revenues collected by a meat tax could be spent in ways to further reduce meat consumption.

In their baseline scenario, the authors find that green labelling has little impact on reducing meat consumption; they also find that the optimal meat tax is quite significant, at more than 67% of the pre-tax price. Of course, different parameterizations could alter the specific findings, but a significant meat tax combined with a supplementary informational campaign seems to me like a big improvement over the status quo.