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IB DP Economics — Unit 2: Microeconomics | SL | 2.7 Role of Government in Microeconomics
📋 What You Will Learn
- Identify and explain the main reasons why governments intervene in markets
- Define price ceilings and price floors and explain the conditions under which they are binding
- Analyse the effects of price ceilings on market outcomes, including shortages and parallel markets
- Analyse the effects of price floors on market outcomes, including surpluses and government purchases
- Apply price control diagrams to real-world contexts including rent controls and minimum wages
- Evaluate the intended and unintended consequences of price controls as government policy tools
🔍 Guiding Question When markets produce outcomes that are efficient but inequitable — or inequitable but efficient — should governments intervene, and what are the real costs of doing so?
🌍 Why This Matters In 2023, Berlin's government capped rents at 2019 levels to protect tenants from soaring housing costs — only to see landlords withdraw properties from the rental market, worsening the very shortage they sought to fix. Meanwhile, the UK raised its National Living Wage to £11.44 per hour in April 2024, sparking debate about whether a wage floor helps low-paid workers or destroys the jobs they depend on. Both policies are price controls — and both illustrate why government intervention in markets is one of the most contested areas of economic policy.
Why Do Governments Intervene in Markets?
Free markets are powerful allocators of resources, but they do not always produce outcomes that are socially desirable. Governments intervene when markets fail to achieve efficiency, equity, or stability. Understanding the reason for intervention is essential — it determines which policy tool is appropriate and how its success should be judged.
The Main Reasons for Government Intervention
- Market failure: when the free market misallocates resources — producing too much or too little of a good relative to the social optimum (e.g. negative externalities from pollution, underprovision of public goods)
- Equity concerns: even when markets are efficient, the resulting distribution of income and access to goods may be considered unfair — governments intervene to protect vulnerable groups (e.g. low-income renters, minimum wage workers)
- Price instability: in markets with volatile prices (agricultural commodities, energy), governments may intervene to stabilise prices for producers or consumers
- Merit goods underconsumption: goods that are undervalued by consumers (e.g. education, healthcare) may be underproduced by the market — governments subsidise or mandate their provision
- Demerit goods overconsumption: goods whose true social costs exceed private costs (e.g. tobacco, alcohol) may be overproduced — governments tax or restrict them
- Macroeconomic objectives: governments may intervene in specific markets to support employment (minimum wage), control inflation (price ceilings), or manage a balance of payments deficit (trade restrictions)
📖 Definition — Government Intervention Government intervention refers to actions taken by the state to alter the outcomes produced by free markets, including price controls, taxes, subsidies, regulations, and direct provision of goods and services.
💡 Key Distinction — Efficiency vs Equity A market can be allocatively efficient (producing at the point where MSB = MSC) yet deeply inequitable — for example, a housing market that clears at a price only wealthy households can afford. Governments must decide whether to prioritise efficiency, equity, or both — and these goals often conflict.
Price Controls — An Overview
Price controls are government-imposed limits on the price at which a good or service can be bought or sold. They are the most direct form of market intervention and come in two forms: a maximum price (price ceiling) and a minimum price (price floor). The critical question for any price control is whether it is binding — that is, whether it actually constrains the market outcome.
📖 Definition — Price Control A price control is a