In my graduate economics training, instructors went to great lengths to try to drive in the difference between normative and positive economic statements. Normative statements are non-falsifiable statements of what should be. Positive statements are potentially falsifiable statements. The ongoing thread on meat consumption reminded me of my struggles understanding the difference.
Before I continue, I have to come clean: I'm an unapologetic meat eater. It has nothing to do with machismo or an American attitude---I just like it. My 4-year old told his teacher, when asked his father's favorite food: Hamburgers. Why do I bring this up? Because my meat eating is probably just as likely to creep into my economic analysis of meat consumption as vegetarians' views are likely to creep into theirs. This is the normative side of economics. So let me try to describe a positive economic analysis of the meat eating issue and then talk a little about how the normative stuff comes in.
To simplify the story, let's take for fact that livestock production in the U.S. accounts for 20% of greenhouse gas emissions (I have no idea if that number is accurate but my meat-eating side hopes not). Again for simplicity I'm going to assume away any other possible side effects of meat production or consumption--like clogged arteries. So the relevant economic question is: Does the fact that 20% of greenhouse gases come from meat production--a positive statement--mean that all meat consumption should stop--a normative statement? The answer is no, no more than the fact that cars produce greenhouse gases means we should stop driving.
From an economic perspective, there are multiple sources of greenhouse gas emissions. Assuming the goal is to reduce greenhouse gas emissions by 20%, what is the economically efficient way to do that. One possible way is to reduce meat production by 100%. Just as eliminating industrial pollution would be expensive and infeasible--zero pollution is not an economically justifiable position--so would eliminating meat production--zero meat consumption is not an economically justifiable position. The utility loss to meat eaters would most assuredly outweigh the benefits of reduced greenhouse gases. So what is the economic solution? Reduce emissions from each source until the marginal benefit of emitting the next unit of greenhouse gases is the same across all sources. How can we do that? The dreaded t-word. Tax greenhouse gas emissions.
Again for simplicity, let's suppose we're only talking about carbon emissions. A carbon tax per unit of carbon emissions will efficiently price carbon and reduce carbon emissions at least cost. Those that benefit most from carbon emissions are willing to pay the most to keep emitting carbon, and those that benefit the least will reduce the most. A price is judgement free--man, I know that's going to cause problems.
So whether your normative view is: we shouldn't eat meat, or we should eat meat, the economic solution is price meat so we are free to choose the amount that produces the largest net benefit...that may be zero, but maybe not.
