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Module 01 of 845 min readAdvanced

What a central bank does

The mandate, the balance sheet, and the case for independence — the Central Bank of Kenya read against the textbook central bank.

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Learning objectives

By the end of this module, you should be able to:

  • 01List the core functions of a central bank and read its balance sheet
  • 02Explain the time-inconsistency case for central-bank independence
  • 03Distinguish goal independence from instrument independence
  • 04Justify the accountability and transparency that independence requires

A central bank is the most powerful unelected economic institution in a country, and one of the least understood. This course opens the black box: what a central bank actually does, why it is given independence from the elected government, and — the recurring theme — why the textbook account of monetary policy fits a developing economy only loosely. We start with the institution itself.

What a central bank does

  • Monetary policy — setting the policy interest rate and managing liquidity to pursue its mandate (usually price stability).
  • Currency issuance — the monopoly on issuing legal tender; the bank's note is the ultimate means of settlement.
  • Banker to the banks and the government — holding banks' reserve accounts, operating the payment system, and managing the government's accounts.
  • Lender of last resort — providing emergency liquidity to solvent-but-illiquid banks in a panic (module 7).
  • Financial stability and supervision — overseeing the banking system (in many countries the central bank is also the bank supervisor).
  • Foreign-exchange management — holding the reserves and (often) intervening in the FX market (module 6).

The balance sheet

Read the balance sheet and you understand the bank

A central bank's balance sheet is the clearest window on what it does. • Assets — foreign-exchange reserves, holdings of government securities, and loans/repos to commercial banks. • Liabilities — currency in circulation (the notes in your wallet are a liability of the central bank), and the reserve balances commercial banks hold at the central bank. Monetary policy operations are changes to this balance sheet: buying securities (open-market operations) injects reserves; selling them withdraws reserves; accumulating FX reserves expands it. The bank's unique power is that it can create its own liabilities (reserves and currency) at will — it can never run out of domestic money — which is the root of both its potency and the danger of fiscal dominance (module 8).

Why independence? The time-inconsistency problem

Kydland-Prescott, applied to inflation

The case for central-bank independence rests on the time-inconsistency result (Kydland-Prescott, 1977, from the Public Choice course). A government that controls monetary policy faces a standing temptation: announce low inflation to anchor expectations, then create a surprise inflation to boost output and erode the real value of its debt before an election. Rational agents foresee this and build the expected inflation into wages and prices — so the economy ends up with high inflation and no output gain (the inflation-bias equilibrium). The solution is to delegate monetary policy to an independent central bank with a clear price-stability mandate, removing the lever from the politicians who would be tempted to abuse it. Rogoff (1985) refined this: appoint a 'conservative central banker' who weights inflation more than the public does, to credibly resist the temptation. The empirical counterpart (Alesina-Summers, 1993): more independent central banks have delivered lower, more stable inflation, with no cost in output volatility — independence appears to be a free lunch in credibility.

Goal versus instrument independence

Independence comes in degrees. Goal independence is the freedom to choose the objective itself (the inflation target); instrument independence is the freedom to choose how to pursue a goal set by the government. Most modern arrangements give the central bank instrument independence but not goal independence — the elected government sets the target (a democratic anchor), and the bank is free to use its tools to hit it without interference. This balances credibility (the bank can resist political pressure on operations) with democratic legitimacy (an unelected body should not choose society's fundamental objectives).

The price of independence: accountability

An independent, powerful, unelected institution must be accountable, or it is illegitimate. The counterpart to independence is therefore transparency and accountability: a clear mandate set in law, published decisions and minutes, regular reporting to the legislature, inflation reports explaining performance against the target, and override or appointment mechanisms that preserve democratic oversight without permitting day-to-day interference. The Central Bank of Kenya, like its peers, operates a Monetary Policy Committee whose decisions and reasoning are published — the transparency that makes independence democratically defensible. Independence without accountability is not credibility; it is unaccountable power.

Exercise

A finance minister, facing an election and a heavy debt-service bill, publicly urges the central bank to cut interest rates and 'support the government'. The central bank has instrument independence and an inflation target set by law. (1) Explain, using time-inconsistency, why the law gives the bank independence precisely to resist this kind of pressure. (2) Distinguish what the bank can and cannot decide given that it has instrument but not goal independence. (3) Explain how a surprise inflation would benefit the government in the short run and why rational expectations defeat it over time. (4) What accountability mechanisms legitimise the bank overriding the minister's wish?

Key takeaways

  • ◆A central bank conducts monetary policy, issues currency, banks the banks and government, is lender of last resort, oversees financial stability, and manages FX reserves
  • ◆Its balance sheet (assets: FX reserves, govt securities, loans to banks; liabilities: currency, bank reserves) is the clearest window on what it does — and it can create its own liabilities at will
  • ◆Independence is justified by time-inconsistency (Kydland-Prescott): delegating to an independent bank with a clear mandate defeats the inflation-bias temptation (Rogoff's conservative central banker; Alesina-Summers' evidence)
  • ◆Most banks have instrument independence (free to use tools) but not goal independence (government sets the target) — balancing credibility with democratic legitimacy
  • ◆Independence requires accountability — a legal mandate, published decisions/minutes, inflation reports, and legislative oversight — or it is unaccountable power

Further reading

  1. 01

    Rules Rather than Discretion: The Inconsistency of Optimal Plans

    Finn Kydland & Edward Prescott · Journal of Political Economy 85(3) · 1977The time-inconsistency result underpinning central-bank independence. The 2004 Nobel work; foundational.

  2. 02

    The Optimal Degree of Commitment to an Intermediate Monetary Target

    Kenneth Rogoff · Quarterly Journal of Economics 100(4) · 1985The 'conservative central banker' solution to inflation bias. The theoretical case for delegation.

  3. 03

    Central Bank Independence and Macroeconomic Performance

    Alberto Alesina & Lawrence Summers · Journal of Money, Credit and Banking 25(2) · 1993The cross-country evidence that independence delivers lower inflation at no output cost. The empirical anchor.

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Module 02

Money, credit, and the transmission mechanism

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