Green growth has been in the news lately with much talk about greening the fiscal stimulus for a triple bottom line. Yet there are worries and the question remains as to whether green growth means slower growth with resources diverted to cleaning up the growth process. And what would happen to countries who unilaterally decide to impose domestic environmental regulations and/or a carbon price?. Will this lead to jobs moving abroad—to poorer or less-green countries that would become pollution havens?
Unfortunately much of the green growth discussion has been of the proselytizing or the scare-mongering kind, with not enough analysis of the potential trade-offs between greening and growing, and not enough thought devoted to ways of minimizing these trade-offs.
In this context, a new paper by Philippe Aghion, Daron Acemoglu and two Harvard graduate students, on “The Environment and Directed Technical Change” (pdf) is a much needed contribution. It also makes for a fascinating read: do not let the large number of equations scare you off! As in all of Aghion’s work, the key insights of the papers are fully captured in crisp writing in the first few pages of the paper.
In his presentation at the World Bank on March 8, Aghion explained the motivation of the paper: most economic models looking at the trade-offs between acting aggressively or not on climate change assume technical change is exogenous—i.e., does not respond to changes in energy prices (for example through a carbon tax) nor to environmental regulation (like a cap on emissions). This results in green growth being slower than dirty growth, at least if the negative impacts of climate change are small, and/or results in the need for permanent subsidies.
