Great! This is the only 'complete' argument I've seen that our prior for animal products industries should be that they are increasing-cost rather than constant-cost. I'm not as confident as you seem to be, but that's more of a quibble at this point, and I'm glad we agree on the meta-prior!

The challenge then is to convince Norwood and Lusk that we want to know the long-run impact of consumer choices on animal production, not the short-run! They're clearly estimating short-run elasticities since (a) their supply curves are way too steep, even for an increasing-cost industry, and (b) they explain their elasticities with an explanation that is irrelevant to the long-run:

Because it takes a year between the time a cow is bred and the time her calf is born, and then it also takes a long period before that cow can be transformed into beef or produce milk, it is difficult for beef and dairy producers to alter production according to changes in consumer preferences.