In my dream, Greg Mankiw and Larry Summers are advising a friend about weight loss.
Mankiw says: If you eat fewer calories, you’ll lose weight.
Summers replies: Not so fast! Sometimes if you eat less ice cream, you crave more cake. Then your calorie intake won’t change and you won’t lose weight. Greg’s advice is fine as an academic theory, but I doubt it will work in practice.
(Note here that Greg never mentioned ice cream in the first place.)
Of course Greg is 100% right, both in theory and in practice. If you eat fewer calories, you will lose weight. Summers responds that if you don’t eat fewer calories, you might not lose weight. True, but entirely off the mark.
I mention this because Mankiw had a recent blog post where he argued that if you cut taxes on capital income you’ll see a big rise in wages. (I happen to have blogged about this twice already in the past 24 hours, but those posts are irrelevant here.) Summers has replied that Mankiw is right in theory but likely to be wrong in practice, and lists three reasons. The first of those reasons comes down to saying that if you cut the corporate income tax, corporations are likely to end up paying more in other taxes, so you haven’t really cut the capital tax after all.
(Note here that Greg never mentioned corporate taxes in the first place.)
Okay, fine. So if you haven’t cut the capital tax, then Greg’s observation doesn’t apply. Likewise, if you haven’t really cut calories, you shouldn’t expect any weight loss. That’s not remotely a refutation.
Continue reading ‘Weight Loss Advice From Big Name Economists’