Here is his Wikipedia page.  Here is some bio.  Here is his 1999 survey on monetary policy.  Here is Google Scholar.  He is a very wise and very accomplished economist.  Here is his piece on what we’ve learned about monetary policy in the last decade, with special reference to the liquidity trap and zero bound.  Excerpt:

According to monetary theory, central banks have at least two powerful – and complementary – tools to reflate a depressed economy: printing money and supporting the nominal price of public and private debt. As Bernanke (2002) himself argues, a determined central bank can deploy both tools for as long as it wants regardless of 1) how credible its commitment is and 2) how expectations are formed or 3) how term or default premia are determined. There are two fundamental questions. First, can these tools, aggressively deployed, eventually generate sufficient expectations of inflation so that they lower real interest rates? Forward looking models generally predict that the answer is yes. However, the interplay between monetary policy and the yield curve can become complex when central banks are at the zero lower bound (Bhansali et. al. 2009) and central banks seek to provide a “deflation put.”

Also, as discussed above, given the prominent role that inflation expectations play in inflation dynamics, inflation inertia is the enemy of reflation once deflation sets in. A second question relates to the monetary transmission mechanism itself. In a neoclassical world that abstracts from financial frictions, a sufficiently low, potentially negative real interest rate can trigger a large enough inter-temporal shift in consumption and investment to close even a large output gap. But in a world where financial intermediation is essential, an impairment in intermediation – a credit crunch – can dilute or even negate the impact of real interest rates on aggregate demand. In the limiting case of a true liquidity trap, no level of the real interest rate is sufficient in and of itself to close the output gap and reflate the economy. Credit markets in the U.S. appear at this writing to be bifurcated.

There is more to say about Clarida but I have to run to dinner and the theater!

Basically I see it as that Obama and Bernanke have chosen two academics — two guys who think monetary policy really works, or at least can really work.  Odds are, they are Ben’s guys, and in my view that is good news.  By the way, Clarida I believe is a Republican.

Addendum: Dylan Matthews has good remarks.

Stein is one of the most creative contemporary economists, with some truly interesting and first-rate papers in the early to mid 1990s.  He has kept up his quality and creativity since then.  Most of the early papers are in mid-brow theory, industrial organization, and signaling.  Here is one of his very recent papers on macroprudential regulation; it stresses the importance of dynamic bank recapitalization. He is a very smart and still underrated economist; he’s one of the few where I will more or less automatically start reading his papers when I run across them.  I have no idea how he would do in the all-important political side of the job.  From the paper, an excerpt:

If significant increases in capital ratios have only small consequences for the rates that banks charge their customers, why do banks generally feel compelled to operate in such a highly-leveraged fashion, in spite of the obvious risks this poses? And why do they deploy armies of lobbyists to fight against increases in their capital requirements? By way of contrast, it should be noted that non-financial firms tend to operate with much less leverage than financial firms, and indeed often appear willing to forego the tax (or other) benefits of debt finance altogether. In Kashyap, Stein and Hanson (2010) we argue that the resolution of this puzzle has to do with the unique nature of competition in financial services. Unlike in many other industries, the most important (and in some cases, essentially the only) competitive advantage that banks bring to bear for many types of transactions is the ability to fund themselves cheaply. Thus if Bank A is forced to adopt a capital structure that raises its cost of funding relative to other intermediaries by only 20 basis points, it may lose most of its business. Contrast this with, say the auto industry, where cheap financing is only one of many possible sources of advantage: a strong brand, quality engineering and customer service, and control over labor and other input costs may all be vastly more important than a 20 basis-point difference in the cost of capital.

Here he argues for a very gradual phase-in of tough capital requirements.  In this paper he argues for a credit-based channel of monetary transmission, and here.  This puts him in an alliance with early Bernanke.  Here is his paper on the cyclical effects of Basel capital standards; he has done a lot of work with Anil Kashyap in that area.  Here is his overly optimistic paper on the eurozone.  In this paper he lays out his generally positive view of the efficacy of monetary policy, with a nod to Hyman Minsky on the debt issue.