Some Major Problems in Monetary Theory
📄 Summarized from the full manuscript · Human-reviewed for faithfulness before publication
In brief
Judging whether monetary policy works means separating two questions: whether the central bank can control the quantity of money, and whether that quantity moves income and prices. This 1961 essay argues the casual evidence traded in policy debates settles neither. Brunner reports that the money stock responds to the monetary base by a factor of roughly 1.5 to 3.5, making the base the dominant control lever and rejecting the British claim that money was uncontrollable, and proposes that policy works by shifting the public's whole balance sheet across many assets, not just money against bonds. It matters because both claims became foundations of monetarism.
What this paper finds — and why it matters
This 1961 American Economic Association Papers and Proceedings essay by Karl Brunner argues that evaluating monetary policy’s effectiveness requires separately and rigorously assessing two distinct theoretical links: how policy actions (open-market operations, reserve requirements, the discount rate) affect monetary aggregates (“money supply theory”), and how monetary aggregates in turn affect income and prices (“money demand theory” combined with aggregate demand theory) — and that casual empirical patterns commonly invoked in policy debates fail to discriminate between rival hypotheses about either link. Brunner outlines a money-supply theory in which the money stock, bank credit, and interest rates are jointly determined in the bank credit market, and reports that partial-correlation estimates across differently-situated sample periods put the “monetary multiplier” (money stock’s response to the monetary base) in the range of 1.5 to 3.5, with the base identified as the single most important determinant of the money stock — explicitly rejecting the UK’s Radcliffe Report’s claim that the money supply was “evidently uncontrolled.” On the demand side, Brunner confirms the basic Keynesian interest-and-income specification but argues Milton Friedman’s permanent-income-based demand function better explains the secular and cyclical behavior of velocity, and reports his own modified versions (adding an interest-rate term) estimated on 1919-1959 annual data, finding significantly negative interest elasticities (around -0.22 to -0.30) dominated by a substantially larger permanent-income elasticity. The essay’s central substantive claim is a “portfolio adjustment” balance-sheet transmission mechanism — monetary policy works because money-stock changes alter the public’s whole balance sheet, triggering asset substitution across the full range of assets and liabilities (not just money versus bonds), which spills over into demand for newly produced goods and assets — and Brunner marshals four types of observational evidence (money-financed deficits and inflation, delayed post-control price adjustment, cross-sectional asset-holding patterns, and aggregate-demand equation fit) as consistent with this view.
Summary of a classic paper, AI-assisted and human-reviewed. See the linked original for the authoritative claims and full conditions.
Questions & answers
Q1. What is the paper’s central methodological argument about evaluating monetary policy effectiveness?
Brunner argues that assessing whether monetary policy is effective requires comparatively appraising rival theories along two separate causal links — policy-to-money (money supply theory) and money-to-income/prices (money demand and aggregate demand theory) — rather than citing casual observational patterns, which he shows can be logically consistent with opposite conclusions about policy effectiveness. He illustrates this with three commonly-cited “facts” (growth of nonbank financial intermediaries, large excess reserves in deflation, and rising velocity under restrictive policy) that are often used to argue monetary policy is losing effectiveness, but which he shows are equally consistent with a hypothesis implying policy remains fully effective — meaning the observations themselves carry no discriminating power between the two views.
Q2. What does Brunner’s money supply theory say, and what empirical support does he report for it?
Brunner models the money stock, bank earning-asset portfolios, and interest rates as jointly determined through equilibrium in the bank-oriented credit market, yielding a “money supply function” in which the monetary base is the dominant determinant of the money stock, with a “monetary multiplier” (the derivative of money supply with respect to the base) estimated in the range of 1.5 to 3.5 across different deflationary and inflationary sample periods. He reports that partial-correlation estimates using monthly or quarterly data confirm the connection between the monetary base, reserve requirements, and the money supply, and that models which disregard the base “yield thoroughly unreliable results or factually erroneous conclusions” — a direct rebuttal of the UK Radcliffe Report’s claim that money supply growth alongside a constant cash ratio meant the money supply was “evidently uncontrolled,” which Brunner attributes to the Report’s neglect of the base’s continuous growth over the preceding decade.
Q3. How does Brunner resolve the debate over whether bank reserves are a “policy variable,” a directly-controlled instrument, or a target signal?
Brunner rejects treating bank reserves as either a direct policy lever or as fully and immediately controlled by policy, and instead argues reserves are an endogenous variable jointly determined (along with the money stock) by the monetary base — not a variable through which policy acts on money in a simple linear chain from base to reserves to money. He supports this with partial Kendall correlation coefficients for 1947-57 quarterly data, reporting that money and the base are far more strongly associated when holding reserves constant (+0.581) than money and reserves are when holding the base constant (0.058) — evidence he reads as more consistent with his joint-determination theory than with a reserves-mediated causal ordering.
Q4. What does the paper conclude about the demand for money, comparing the Keynesian and Friedman formulations?
Brunner confirms the basic Keynesian money-demand specification (desired balances rising with income and falling with the interest rate) using both quarterly 1939-57 and annual 1929-59 data, but argues Milton Friedman’s permanent-income-based demand function is more highly corroborated because it explains both the secular and cyclical behavior of money’s velocity, which the Keynesian formulation does not. He notes the Friedman hypothesis nonetheless shows sizeable gaps between actual and estimated velocity in the 1930s and 1950s that appear related to differences in interest-rate levels across the two periods, motivating his own two modified specifications.
Q5. What are Brunner’s own modified demand-for-money estimates, and what do they find?
Brunner augments Friedman’s permanent-income demand function with an interest-rate term in two variants — one substituting current prices, one substituting transitory income for permanent prices — estimated on annual data from 1919 to 1959 across several subperiods, finding statistically significant negative interest elasticities clustering between -0.22 and -0.27 (with one exception in a low-power subperiod), and a permanent-income elasticity that “dominates persistently,” running roughly three times the size of the interest elasticity. Appendix B reports three related total-sample specifications with multiple correlation coefficients of 0.990-0.993, interest elasticities of about -0.22 to -0.30, and income/wealth elasticities of 1.5-1.7.
Q6. What is the “portfolio adjustment” transmission mechanism Brunner proposes, and how does it differ from a net-worth-only view?
Brunner argues that monetary policy transmits to output through a balance-sheet, or portfolio-adjustment, mechanism: changes in the public’s money balances alter its whole inherited asset-and-liability position, inducing substitution not just between money and bonds but across the entire spectrum of assets, which spills over into new production of assets, goods, and services. He contrasts this with a “net worth hypothesis” under which only total net worth (not its composition) matters for demand behavior, implying — among other things — that the degree of inflation from a money-financed government deficit would be independent of the size of the monetary multiplier; Brunner treats this as an open, unresolved question with “far-reaching ramifications” for how nonbanking financial intermediaries and new government security issues should be interpreted.
Q7. What observational evidence does Brunner offer in support of the portfolio-adjustment view?
Brunner cites four patterns he argues are consistent with the portfolio-adjustment mechanism and difficult to reconcile with theories that ignore balance-sheet interdependence: (1) money-financed government deficits have “without exception” been associated with rising prices, with stabilization occurring only once the link between the deficit and base growth was broken; (2) removing wartime price controls after a period of money-balance accumulation is followed by a delayed price-level increase as actual balances adjust to desired levels; (3) cross-sectional data show money balances are not randomly distributed relative to other components of wealth, with larger money balances associated with larger holdings of other assets and liabilities; and (4) aggregate-demand equations that include monetary variables outperform those that exclude them, particularly in periods of large money-stock variation. He is explicit that these observations do not establish a particular class of monetary theories but “constitute a case for considerable investment of resources” in further investigating the policy-to-target chain.
Q8. What are the scope and limitations of the paper as Brunner presents them?
Brunner frames the essay’s empirical content as illustrative and preliminary rather than definitive: the money-supply appendix reports coefficient estimates from two specific, “deliberately selected” sample periods (a Depression-era window and 1929-1940) rather than a comprehensive test, and the paper closes by describing a “diligent search for more fruitful hypotheses” as still “under way,” with the demand-for-money modifications explicitly framed as tentative refinements of the Friedman approach rather than a settled alternative. The paper does not attempt policy prescriptions or an assessment of any specific historical Federal Reserve action; its stated aim is establishing the two-subrelation framework and illustrating, rather than definitively resolving, the comparative empirical case for the money-supply and portfolio-adjustment theories it favors.
Key terms in this paper
Definitions below follow the paper's own usage.
- money supply theory
- the branch of monetary theory explaining how policy variables (open-market operations, reserve requirements, the discount rate) determine monetary aggregates, formalized here as a joint equilibrium of bank asset demand, public asset supply, and central-bank borrowing in the bank-oriented credit market.
- monetary base
- the amount of money directly issued by the monetary authorities (here, the "adjusted" base excludes discounts and advances); identified in the paper as the single most important determinant of the money stock, with a "monetary multiplier" (money stock's derivative with respect to the base) estimated at 1.5 to 3.5 across sample periods.
- portfolio adjustment (balance-sheet) mechanism
- the paper's proposed transmission channel from money to output, in which a change in money balances alters the public's whole asset-and-liability position, triggering substitution across the full range of assets (not only money and bonds) that spills over into new production of goods, services, and assets.
- net worth hypothesis
- the rival view, described but not adopted by Brunner, that only the level of net worth (not its composition across asset types) affects aggregate demand — implying, for instance, that the inflationary effect of a money-financed deficit would not depend on the size of the monetary multiplier.
- Friedman's permanent-income demand for money
- Milton Friedman's demand-for-money specification relating desired balances to a wealth index built from permanent (rather than current) income and population, which Brunner finds explains the secular and cyclical behavior of money's velocity better than the Keynesian income-and-interest-rate specification, subject to noted gaps between actual and predicted velocity in some periods.