Environmental economics & policy
Market Instrument
A policy tool that uses prices or markets — taxes, tradable permits, subsidies, charges — to make polluters internalise environmental costs rather than prescribing behaviour by command.
Definition
Market (or market-based) instruments are environmental policy tools that alter prices or create markets to steer behaviour: emissions taxes and charges, cap-and-trade systems, subsidies and tax credits, deposit-refund schemes and tradable quotas. The 1990 US Clean Air Act sulphur dioxide trading programme is widely regarded as the watershed demonstration that such instruments can cut pollution at lower cost than command-and-control regulation.
References
instrument taxonomy, 1990 Clean Air Act SO2 trading as watershed case
Overview
What it means
Instead of mandating technologies, market instruments set the incentive and let actors find the cheapest abatement — achieving a given environmental target at lower aggregate cost, and generating revenue (taxes) or allocating scarcity (permits).
How it is used
Carbon pricing schemes (EU ETS, carbon taxes), renewable energy certificates, plastic bag charges and water trading all apply market-instrument logic; policy design debates concern price levels, allocation, equity and market stability.
Why it matters
Market instruments are the dominant architecture of modern climate policy; their design determines whether decarbonisation happens efficiently and fairly. **Note:** In-batch merge: 1714 (market-based instrument) → this entry.
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