Economic experiments support Ostrom's polycentric approach to mitigating climate change.

Area of Science:

• Environmental Science
• Behavioral Economics
• Political Science

Background:

• Global climate change mitigation efforts have yet to yield an effective global treaty.
• Elinor Ostrom proposed a polycentric approach, emphasizing decentralized governance over centralized solutions.
• Many global problems arise from cumulative actions of diverse actors, from individuals to governments.

Purpose of the Study:

• To provide experimental economic support for Elinor Ostrom's polycentric governance ideas for climate change mitigation.
• To test the effectiveness of incentivized, subgroup-based climate action versus centrally sanctioned approaches.

Main Methods:

• Experimental economics was used to simulate climate change mitigation scenarios.
• Experimental populations were divided into subgroups, each pursuing sub-goals with incentives.
• The impact of incentivizing subgroup contributions and sanctioning free-riders was compared.

Main Results:

• Polycentric approaches, where subgroups achieved sub-goals with incentives, successfully met the global threshold for averting simulated climate change.
• Incentives for energy saving motivated subgroups to reach their targets.
• Costly sanctions against free-riding subgroups proved ineffective, negatively impacting contributions from fair individuals.

Conclusions:

• Polycentric governance, leveraging numerous successful, decentralized units, is a powerful strategy for mitigating climate change.
• Incentivizing individual and small-scale actions can lead to significant global emission reductions.
• Coercive sanctions are less effective than positive incentives in polycentric climate change mitigation efforts.