Definition for "premia"

Does anybody out there have an online dictionary that has the definition for premia. The normal Merriam-Webster online dictionary says it's in their unabridged dictionary which I'm too cheap to pay for, and Dictionary.com doesn't have it at all.

I believe that it is simply the plural of premium.

The usage I saw was in a speech by the President of the Federal Reserve Bank of New York (now you know how I spend my spare time):

Perhaps it makes sense to conclude with the more general observation that changes in the size of balance sheets increase the importance of sustaining the credibility of monetary policy, because they increase the costs of a loss of credibility or a negative shock to credibility. We live with considerable uncertainty about the sustainability of the pattern of relatively low risk premia and reduction in the cost of insurance against future macroeconomic and financial volatility. That uncertainty necessarily adds to the normally substantial degree of uncertainty we face in making monetary policy judgments. All these factors strengthen the case for being open about what we do not know. And it reinforces the case for preserving confidence in our commitment to keep underlying inflation low over time, and for retaining the capacity to respond with flexibility to the challenges we face in this uncertain world.

So, actually, the term I really need a definition for is risk premia, which I believe is the plural of risk premium.

Maybe this is just an excuse for me to buy a full-blown OED dictionary and be done with it, but the OED Online costs $295 per year or $29.95 per month.

-- Jack Krupansky