Robert Barro Talks Stimulus

Josh Wright —  6 February 2009

Here’s the link.  Its an accessible read.  Here’s a few key question (in bold) and answers:

Do you read Paul Krugman’s blog?

Just when he writes nasty individual comments that people forward.

Oh, well he wrote a series of posts saying he thought the World War II spending evidence was not good, for a variety of reasons, but I guess…

He said elsewhere that it was good and that it was what got us out of the depression. He just says whatever is convenient for his political argument. He doesn’t behave like an economist. And the guy has never done any work in Keynesian macroeconomics, which I actually did. He has never even done any work on that. His work is in trade stuff. He did excellent work, but it has nothing to do with what he’s writing about.

I would need to go back and check. But one question, and I think Greg Mankiw raises this question as well, is, Why does this set of evidence depart from what seems like the standard Keynesian theory that a dollar of spending would have a larger multiplier than a dollar of tax cutting?

I don’t think it is really confusing at all, because when you cut taxes there are two different effects. One is that you cut tax rates, and therefore give people incentives to do things like work and produce more and pay more — maybe, depending on what kind of taxes. And then you also maybe give people more income. This income effect is the one that’s related to this Keynesian multiplier argument, where it’s usually argued that government spending should have a bigger effect. So that’s the income effect. But the tax-rate effect, inducing people to do things like work and produce more and invest more, is a whole separate effect, and that could easily be much bigger than the multiplier thing, than the income thing.

This might just be my confusion, but the inducement to work, is separate from the idea of boosting aggregate demand and consumption in the short run.

Oh it’s exceptionally different. But the experiment is that the government is doing something by changing the tax system to lower its collections — by, for example, a tax cut. The response of the economy to that is not going just to isolate this business of giving people money. It’s also going to have these incentive effects, more than tax rebates, on economic activity. It’s going to be a combination of those two things — income effects and incentive effects. One piece looks like this sort of multiplier stuff, which is analogous to government spending — probably because the government spending has a first-round effect where it comes in and directly affects the aggregate demand — and then in the second round it sort of looks like a tax cut. That’s why the government spending thing is bigger in textbooks: because it has this first round in addition to all these subsequent ones.

But all that is just income responses — people having more or less income, or the government keeping the money and then that shows up as people’s income.  None of that is about responses in terms of incentives — incentives changing in response to lower or higher tax rates. And the evidence that Romer and Romer look at is combining the tax rate stuff with the income stuff. I didn’t know it was possible to do that but, hey, you get different viewpoints form different people. But the study I am doing now is intended to include all these things together in one framework.