98eef080_r_Climate_and_Energy_Solutions__Expansion
[Policy] Cap-and-Trade [Innovation] Yes - firms have incentive to innovate to reduce emissions and avoid buying allowances (or to have more excess allowances to sell). [Compliance Cost Certainty] No - difficult for policymakers to foresee the price of allowances in a tradable open market (can be mitigated with price bands). [Environmental Certainty] Yes - a cap on emissions means that the total level of emissions is known (certainty reduced with price cap or floor). [Linkability] Yes - new regions can be included or merged into a trading program (may be complicated by price bands). [Revenue Recycling] Depends on if allowances are allocated for free or if they are auctioned to raise public revenues. [Expansion] 
Yes - can be expanded to other sectors or regions.
Market Mechanisms: Understanding the Options | Center for Climate and Energy Solutions
Expansion