Scientists? Engineers? How about Gardeners?

In the past few days Simon Wren-Lewis (at Mainly Macro) and Noah Smith (at Noahpinion) have revisited some past musings by Greg Mankiw on whether we should think of macroeconomists as scientists or engineers. The separation between the two in Mankiw’s telling occurs at the point where macroeconomics meets policy—when macroeconomists leave the academic cloister and take up the causes of the real world. In Mankiw’s original words:

God put macroeconomists on earth not to propose and test elegant theories but to solve practical problems.

Wren-Lewis and Smith each have their own issues with the scientist/engineer taxonomy, but both seem to more or less buy into the notion of macroeconomist cum policymaker as an engineer.

For my part, I’m not a fan of the engineer metaphor. It seems a little—well, immodest. Consider these comments, to take just a select few, from Federal Reserve officials following the decision of the most recent Federal Open Market Committee (FOMC) meeting. First, from Fed Chairman Ben Bernanke (via Econbrowser):

The policies that we have undertaken have had real benefits for the economy in that they have provided some support, that they have eased financial conditions and helped reduce unemployment. All that being said, monetary policy, as I’ve said many times, is not a panacea, it is not by itself able to solve these problems. We are looking for policymakers in other areas to do their part. We will do our part and we will try to make sure that unemployment moves in the right direction, but we can’t solve this problem by ourselves.

And this, from a September 18 speech by Chicago Fed President Charles Evans:

Given the slow and fragile recovery, the large resource gaps that still exist, and the large risks we face, it remains clear that we needed a more resilient economy that can withstand the headwinds that might come its way. Last week the FOMC provided a more accommodative monetary policy that can help us achieve such resilience.

Or this, from a September 21 speech by Atlanta Fed President Dennis Lockhart:

The core rationale of my support [for the FOMC decision] was to better assure that the economy remains on a growth trajectory sufficient to steadily, if gradually, reduce the rate of national joblessness. I am not expecting miracles.

I think the action recently taken by the committee has improved the country’s economic prospects by reducing the potential downside apparent in the incoming data. In this sense, the policy action was a preventative. But I expect policy will do more than just prevent backsliding.

To be sure, each of the three express confidence that the FOMC’s actions will yield better outcomes than would otherwise occur. I guess you could say “engineer” better outcomes, if you like. But I am struck by some of the other ideas expressed in these comments, related to reducing downside potential, promoting resilience, and providing some support.

I credit my colleague Mike Bryan (who credits former Cleveland Fed President Jerry Jordan, our mutual former boss) for suggesting that these types of motivations are better associated with gardening than engineering science. The good gardener does not presume to create growth, but knows that he or she can play a part by ensuring that growing conditions are the best that they can be. The gardener cannot make the sun shine by applying scientific knowledge, but can take measures to promote resilience and support until it does.

Science and engineering are important, without doubt. But when it comes to policymakers, I’ll take a green thumb any day.

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