Skip to main content
The Timing of Environmental Policy: The Role of Product Differentiation
Journal of Regulatory Economics (2002)
  • Joanna Poyago-Theotoky, Loughborough University
  • Khemarat Talenrngsri Teerasuwannajak, Chulalongkorn University

We examine the role that product differentiation can play in the design of environmental policy under full commitment and no commitment on the part of the environmental regulator. We consider a setting with two firms selling a differentiated product which generates pollution through emissions. Firms can reduce their emissions by undertaking abatement activities while an environmental regulator taxes emissions. The main results are: (1) When products are highly differentiated, the optimal time-consistent (no commitment) tax is always lower than the optimal pre-commitment tax. As the degree of product differentiation decreases, for relatively efficient abatement technology and high damages, the time-consistent emission tax exceeds the optimal pre-commitment one. (2) Abatement when product differentiation is extensive is higher under the time-consistent regime unless the abatement technology is extremely efficient. The same ranking applies to social welfare. However, as products become more and more similar, these results are (partially) reversed and pre-commitment could lead to both higher levels of abatement and welfare.

Publication Date
Citation Information
Joanna Poyago-Theotoky and Khemarat Talenrngsri Teerasuwannajak. "The Timing of Environmental Policy: The Role of Product Differentiation" Journal of Regulatory Economics Vol. 21 Iss. 3 (2002)
Available at: