Econ 101: Interest Rates –Another Go

A month ago I reviewed the role of the Federal Reserve’s policy interest rate: https://wcoats.blog/2025/07/17/the-feds-policy-interest-rate/   The subject is so important and seemingly misunderstand by many that I am reviewing it again here.

Interest rates balance the supply and demand for financial assets. Households and firms that save some of their incomes demand financial assets. Households and firms that borrow to invest in productive capital or for whatever reason supply those assets (mortgages, bonds, etc.). Rates on longer term assets reflect the expected value of the short-term rates over that period. Thus the interest rate on a ten year bond reflects the expected value of one year bills over the ten year period plus a small risk premium because the string of short term loans are an alternative to the single fixed rate ten year loan.

The policy interest rate of the Federal Reserve is set by the Fed to pursue its objective of stable money (defined by the Fed as 2% inflation) and high employment (the Fed’s dual mandate imposed by Congress).

This note reviews the Fed’s policy rate. Since 2008 the Fed’s policy rate has been the rate it pays banks for the money they keep on deposit with a Federal Reserve Bank (of which there are twelve but that is unimportant for understanding the role of the policy rate), which on Aug 6 amounted to $3,332 billion. This rate is known as the Interest on Reserve Balances (IORB).

If the IORB matches comparable market rates for equally liquid funds (the so-called neutral rate), banks will maintain their existing Fed deposits. If it is set above that level, banks will have a financial incentive to place more money with the Fed, i.e. lend less in the market, thus creating fewer deposits and reducing the money supply. If the IORB is set lower than the neutral rate, banks will draw down their Fed deposits to lend more in the market thus increasing deposits and the money supply.

The IORB is currently (Aug 6) 4.5%, where it has remained since Dec 2024. At this rate broad money (M2=bank demand, time and savings deposits) has grown between 4% and 5% (from a year earlier) over the last three months. Given that inflation remains above the Fed’s target of 2% it would not seem wise to lower the policy rate and increase the rate of monetary growth especially as higher tariffs go into effect.

To repeat from earlier blogs (because it is so important), if markets anticipate higher inflation in the future (next few years), market interest rates on longer term debt will increase to preserve their real (inflation adjusted) value. Lowering the Fed’s policy rate prematurely would increase the market’s anticipation of higher inflation rates in the future. In other word, lowering the IORB now is likely to increase interest rates on longer term debt. Leave the Fed alone to do its job as best it can.

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Author: Warren Coats

I specialize in advising central banks on monetary policy and the development of the capacity to formulate and implement monetary policy.  I joined the International Monetary Fund in 1975 from which I retired in 2003 as Assistant Director of the Monetary and Financial Systems Department. While at the IMF I led or participated in missions to the central banks of over twenty countries (including Afghanistan, Bosnia, Croatia, Egypt, Iraq, Israel, Kazakhstan, Kenya, Kosovo, Kyrgystan, Moldova, Serbia, Turkey, West Bank and Gaza Strip, and Zimbabwe) and was seconded as a visiting economist to the Board of Governors of the Federal Reserve System (1979-80), and to the World Bank's World Development Report team in 1989.  After retirement from the IMF I was a member of the Board of the Cayman Islands Monetary Authority from 2003-10 and of the editorial board of the Cayman Financial Review from 2010-2017.  Prior to joining the IMF I was Assistant Prof of Economics at UVa from 1970-75.  I am currently a fellow of Johns Hopkins Krieger School of Arts and Sciences, Institute for Applied Economics, Global Health, and the Study of Business Enterprise.  In March 2019 Central Banking Journal awarded me for my “Outstanding Contribution for Capacity Building.”  My recent books are One Currency for Bosnia: Creating the Central Bank of Bosnia and Herzegovina; My Travels in the Former Soviet Union; My Travels to Afghanistan; My Travels to Jerusalem; and My Travels to Baghdad. I have a BA in Economics from the UC Berkeley and a PhD in Economics from the University of Chicago. My dissertation committee was chaired by Milton Friedman and included Robert J. Gordon. I live in National Landing Va 22202

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