Understanding Markets with Socially Responsible Consumers by Marc Kaufmann

Experimental Economics Research Seminar Series, Autumn Term 2023

  • Wed 22 Nov 23

    11:00 - 12:30

  • Colchester Campus

    Economics Common Room 5B.307

  • Event speaker

    Marc Kaufmann

  • Event type

    Lectures, talks and seminars
    Experimental Economics Seminar Series

  • Event organiser

    Economics, Department of

Join us for this week's event in the Experimental Economics Seminar Series, Autumn Term 2023

Join Marc Kaufmann, from Central European University, as they present their research on Understanding Markets with Socially Responsible Consumers.


Many consumers care about climate change and other externalities associated with their purchases. We analyze the market behavior of such “socially responsible consumers,” derive properties of the resulting competitive equilibria, and assess the effectiveness of different policies. In violation of price taking, a vanishingly small consumer cares about her impact on the market equilibrium to a non-vanishing extent. Specifically, other participants dampen the consumer’s direct effect on the externality, undermining responsible behavior. Dampening implies that even if all consumers value the externality akin to the social planner, they mitigate too little in any equilibrium, and may coordinate on the worst of multiple equilibria. To motivate consumers to lower the externality in a closed economy, a unit tax is superior to a cap-and-trade system, but there are policies that are better than a tax. Furthermore, under trade with a large or very polluting partner, a cap is better than a tax. When there are two products that are perfect substitutes in consumption but generate different externalities, there is always a “selfish equilibrium,” in which the products have the same price and consumers are indifferent between them. Under conditions we identify, the selfish equilibrium is the unique equilibrium. In a selfish equilibrium, a cap and a unit tax on the dirty product achieve the same outcomes. In non-selfish equilibria, a proportional subsidy on the clean product dominates both a unit tax and a cap.

This seminar will be held in the Economics Common Room on Wednesday 22nd November 2023 at 11.00am. This event is open to all levels of study and is also open to the public. To register your place, please contact the seminar organisers.

This event is part of the Experimental Economics Research Seminar Series.