Also, if a group of urban westerners WERE to stop eating such a large quantity of meat en masse, it would have the effect of lowering the price of meat and not the effect of simply reducing the meat eaten in the world. Most of that meat will just get bought by others for a slightly cheaper price. Making protein cheaper for poorer people in the world would arguably be the best outcome of this experiment if the magnitude were anything close to their estimates.
You're right to consider the marginal effect that this might have on the purchasing habits of meat eaters, but you're wrong to ignore the marginal effect that the fall in prices will have on meat producers.
A fall in price will always reduce the quantity supplied, ceteris paribus.
> Also, if a group of urban westerners WERE to stop eating such a large quantity of meat en masse, it would have the effect of lowering the price of meat and not the effect of simply reducing the meat eaten in the world.
This is equivalent to claiming that demand for meat is purely elastic and that the market for meat is frictionless with respect to shipping worldwide.
