Periergia

money & banking

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Money and banking is the study of how societies create and circulate the means of payment, and how the institutions that issue credit and hold deposits shape the value of that money and the stability of the economy.

The Object of Study

Money and banking sits at the intersection of monetary theory, financial intermediation, and macroeconomic policy. The field's central puzzle is deceptively simple: money is a social convention with almost no intrinsic value, yet its supply, distribution, and the leverage built atop it determine employment, inflation, and the recurrence of financial crises. Two research programs organize the modern literature. The first, descending from Knut Wicksell (Interest and Prices, 1898) through Michael Woodford (Interest and Prices, 2003), treats banking as largely a veil and focuses on the interest rate as the operative instrument. The second, associated with Hyman Minsky, Ben Bernanke, and the post-2008 macro-finance literature, insists that the structure of intermediation and leverage is causally primary. The tension between these programs is not settled.

What Money Is: Three Competing Ontologies

There is no consensus on money's essence, and the disagreement is substantive, not semantic.

  • The commodity/metallist view (Carl Menger, "On the Origins of Money," 1892) derives money endogenously from barter as the most saleable commodity. Menger's spontaneous-order account remains elegant but is empirically embattled.
  • The chartalist/state-money view (Georg Friedrich Knapp, Staatliche Theorie des Geldes, 1905; revived by Modern Monetary Theory, Wray, Tcherneva) holds that money is a creature of law and taxation—the state defines the unit of account and drives demand by imposing tax liabilities denominated in it.
  • The credit theory of money (Alfred Mitchell-Innes, 1913; anthropologically extended by David Graeber, Debt, 2011) treats money as transferable debt, with the coin a mere token of a credit relationship.

The anthropological record (Caroline Humphrey's work on the absence of documented barter economies) has largely undermined the Mengerian myth of barter-to-money, though the logical validity of his sequential-saleability argument survives independent of its historical accuracy. This is an active edge case: the origin question and the function question are distinct, and conflating them produces persistent confusion.

Banks Do Not Intermediate Loanable Funds

The most important empirical correction of the past two decades concerns money creation. The textbook loanable-funds / money-multiplier model—deposits fund loans, reserves constrain lending via a multiplier—is now rejected by the very central banks that once taught it. The Bank of England's landmark bulletin (McLeay, Radia & Thomas, "Money Creation in the Modern Economy," 2014) states plainly that commercial banks create deposits ex nihilo when they lend; loans create deposits, not the reverse. Reserves are a settlement asset supplied elastically by the central bank, not a binding quantity constraint under a corridor or floor system.

This endogenous-money position, long argued by post-Keynesians (Nicholas Kaldor, Basil Moore's Horizontalists and Verticalists, 1988), has profound implications:

  • The central bank sets the price of reserves (the policy rate), and the quantity of broad money is demand-determined by creditworthy borrowing.
  • Monetarist quantity-theoretic control of M via the base (Milton Friedman's k-percent rule) is operationally incoherent under modern institutional arrangements, a point the failure of monetary-aggregate targeting in the early 1980s (the Volcker experiment, 1979–1982) demonstrated in practice.

Werner (2014, 2016) provided the first empirical test at the level of an individual bank transaction, corroborating credit-creation over intermediation. Open question: if banks create money, what does constrain aggregate lending—capital regulation, risk appetite, borrower demand, or the term structure? The answer is contested and regime-dependent.

The Interest Rate, the Natural Rate, and Its Discontents

Wicksell's distinction between the natural rate (r*) equating saving and investment at full employment and the market rate set by banks is the backbone of modern central banking. When the market rate falls below r*, cumulative inflation results. Woodford formalized this in the New Keynesian framework, where policy stabilizes the output gap by tracking a time-varying r*.

The post-2008 collapse of estimated r* toward or below zero (Laubach–Williams, 2003 and later; Holston–Laubach–Williams, 2017) revived secular stagnation (Alvin Hansen, 1938; Lawrence Summers, 2013) and exposed the effective lower bound as a first-order constraint. This generated:

  • Unconventional policy: quantitative easing (Bank of Japan pioneered QE, 2001; Fed's LSAPs from 2008), forward guidance, negative rates (ECB and others from 2014). Whether QE works through portfolio-balance, signaling, or fiscal channels remains disputed; the equivalence of QE to debt-maturity management (Wallace neutrality, 1981) is a live theoretical objection.
  • A renewed fiscal–monetary debate: the Fiscal Theory of the Price Level (Leeper 1991; Sims; Cochrane, The Fiscal Theory of the Price Level, 2023) argues the price level is determined by the government's intertemporal budget constraint, not by monetary policy alone. This directly challenges the Woodfordian consensus and has gained traction amid the 2021–2023 inflation surge, which many read as a fiscal-dominance episode following pandemic transfers.

Financial Fragility and the Lender of Last Resort

Banking's defining vulnerability is the maturity/liquidity transformation that makes it socially useful and privately fragile. The canonical formalization is Diamond–Dybvig (1983): demandable deposits funding illiquid assets admit two equilibria, one of which is a self-fulfilling run. Deposit insurance and suspension of convertibility are the standard remedies—each with moral-hazard costs.

The lender-of-last-resort doctrine traces to Henry Thornton (1802) and Walter Bagehot (Lombard Street, 1873): lend freely, against good collateral, at a penalty rate. The 2007–2009 crisis revealed that runs now occur in the shadow banking system—repo, money-market funds, ABCP—on institutions without deposit insurance (Gorton & Metrick, "Securitized Banking and the Run on Repo," 2012). This forced central banks into market-maker-of-last-resort roles far beyond Bagehot's frame, reprised in March 2020's dash-for-cash and the March 2023 regional-bank failures (Silicon Valley Bank), where uninsured deposits and unhedged interest-rate risk on held-to-maturity portfolios produced a modern run at digital speed.

Minsky's financial instability hypothesis—that stability breeds leverage and endogenous fragility (hedge → speculative → Ponzi financing)—was largely ignored by pre-crisis DSGE models, which assumed frictionless finance. The Bernanke–Gertler–Gilchrist financial accelerator (1999) and Kiyotaki–Moore collateral-constraint models (1997) reintroduced finance, but the full integration of intermediary balance sheets (He & Krishnamurthy; Brunnermeier & Sannikov, 2014) remains an active frontier. Open question: can macroprudential regulation (Basel III countercyclical buffers) durably contain endogenous leverage cycles, or does regulation merely relocate them?

Central Bank Digital Currency and the Future of the Deposit

The current institutional frontier is CBDC. If a central bank offers households a direct digital liability, it competes with commercial-bank deposits, potentially disintermediating banks and altering run dynamics (a CBDC could make runs easier, or, if well-designed, safer). This reopens the 1930s Chicago Plan / narrow-banking debate (Fisher, 1936; recently Benes & Kumhof, IMF, 2012) about fully separating money creation from credit provision. China's e-CNY (piloted from 2020), the ECB's digital-euro project, and the Fed's cautious FedNow/CBDC research make this a policy-live question. Whether money should remain a hybrid public-private construct, or migrate toward a public monopoly on the medium of exchange, is arguably the discipline's central open problem for the coming decades.

Persistent Open Questions

  1. What determines the price level when banking is endogenous and the ELB binds—monetary rules, fiscal solvency, or expectations coordination?
  2. What is the correct microfoundation for money's value? Search-theoretic models (Kiyotaki–Wright, 1989; Lagos–Wright, 2005) rationalize a medium of exchange but struggle with fiat money's fragility and the role of the state.
  3. Can financial crises be modeled ex ante, or are they intrinsically Knightian/reflexive events resistant to equilibrium formalization?
  4. What is the optimal boundary of the public balance sheet as central banks become permanent market-makers and potential deposit-issuers?

The field's intellectual history is a pendulum between treating money as neutral veil and as the load-bearing structure of the economy. Each major crisis—1873, 1907, 1931, 2008, 2020—has swung it back toward the latter.