Ignoring Positive Externalities

by Levi Russell

Recently ag economist Jayson Lusk visited UGA to speak on the future of food and the "food movement." One great point he made is that food is quite abundant now relative to any time in the past, and yet there is a very lucrative book and movie industry built around concerns with our food supply. Certainly our food system is far from perfect, but absolute poverty on a global scale has been curtailed dramatically.

A question from the audience particularly interested me: what about externalities related to our current food production methods such as pollution? Lusk's answer was very good. He acknowledged the existence of both negative and positive externalities in food production. He went on to state that both should be considered when designing policy. It certainly seems to me that a lot of attention is paid to the negative externalities associated with food production in the policy world and in the economics profession; relatively little attention is paid to measuring the positive externalities such as the fact that on average Americans spend only about 10% of their disposable income on food and are free to pursue all sorts of other interests.

This discussion reminded me of a paper I read awhile back. It's ungated, and I encourage you to read it if you're interested in this stuff. Here's the abstract:

This paper criticizes the treatment of externalities presented in modern undergraduate economic textbooks. Despite a tremendous scholarly push-back since 1920 to Pigou’s path-breaking writings, modern textbook authors fail to synthesize important critiques and extensions of externality theory and policy, especially those spawned by Coase. The typical textbook treatment: 1) makes no distinction between pecuniary and technological externalities; 2) is silent about the invisible hand’s unintended and emergent consequences as a positive externality; 3) overemphasizes negative externalities over positive ones; 4) ignores Coase’s critique of Pigouvian tax “solutions;” and 5) ignores the potential relevance of inframarginal external benefits in discussions of policy “solutions” to negative externalities. Aside from presentations of “The Coase Theorem” excerpted from only 4 pages of Coase’s voluminous writings, it is as though the typical textbook author slept through nearly a century of scholarly critique of Pigou.