Trading Mechanics

From cap-setting to compliance: understanding market operations

Cap-and-Trade: The Core Mechanism

Most compliance markets use cap-and-trade. Understanding the mechanics is key to seeing how markets drive emissions down.

🏭 Cap-and-Trade Simulator

Your Company Profile:

100 tonnes
80 permits
$50/tonne
$40/credit
⚠️
Deficit: 20 tonnes
You need to buy credits or reduce emissions

Strategy Options:

Buy Credits
$800
Purchase 20 credits at $40/credit
Reduce Emissions
$1,000
Invest in abatement to reduce by 20 tonnes
Hybrid Approach
$400
⭐ Most Cost-Effective
Reduce half, buy credits for the rest

Economic Logic: Credits ($40) are cheaper than your abatement cost ($50)—buy credits in the market!

How Trading Works:

🎯
Step 1: Cap Set

Government sets emissions cap and allocates allowances

You have 80 allowances but emit 100 tonnes

Key Market Design Elements

🎯 Setting the Cap

  • Absolute cap: Total emissions limit (e.g., 100 Mt CO₂/year)
  • Declining trajectory: Cap reduces over time (e.g., 2% annually)
  • Science-based: Aligned with climate targets and carbon budgets

📋 Allowance Allocation

  • Auction: Government sells allowances to highest bidders (most efficient)
  • Free allocation: Grandfathering based on historical emissions or benchmarks
  • Hybrid: Mix of auction and free (common for competitiveness concerns)

💱 Trading & Compliance

  • Secondary trading: Entities buy/sell allowances at market prices
  • Banking: Save unused allowances for future periods
  • Surrender requirement: Must submit credits equal to verified emissions

🛡️ Price Stabilization

  • Price floor: Minimum auction price prevents collapse (e.g., RGGI $3)
  • Price ceiling/reserve: Release extra allowances if price spikes
  • Market Stability Reserve (MSR): EU ETS adjusts supply dynamically

💡 The Economic Elegance of Cap-and-Trade

Cap-and-trade achieves environmental certainty (the cap) and economic efficiency (lowest-cost reductions found through trading) simultaneously. Unlike carbon taxes (price certainty, quantity uncertainty), cap-and-trade guarantees emissions outcome.

Coase Theorem in action: When property rights are clear (allowances) and transaction costs low, trading reaches efficient allocation regardless of initial distribution.