Modeling Energy Use and Technological Change for Policy Makers: Campbell Watkins’ Contribution as a Researcher-Practitioner

As an energy-economics modeler, who collaborated with academics while also consulting to government and industry, Campbell Watkins was especially interested in the empirical relationship between energy inputs and economic output. His skills were perfectly suited to this pressing research issue, which first emerged in the mid-1970s as the “energy-capital substitution” controversy. As his publication record shows, he worked with leading researchers in the development and econometric testing of dynamic specifications of this relationship. But he conducted this work always with a concern for how the research might be useful for immediate policy decisions. Today, the key policy question is the extent to which humanity can reduce its energy-related greenhouse gas emissions at reasonable cost. A new generation of “hybrid, topdown/bottom-up” models attempts to address the objectives Campbell listed in his widely circulated 1992 book chapter, particularly his point that technological change should not be treated as completely exogenous, but at least in part as a very long-run response to price changes and policies. But while current energy models are increasingly constructed to incorporate this feedback effect – notably those models used for simulating climate policies – the empirical estimation of their key parameters is still in its infancy. As Campbell noted in his characteristic dry humor, the scope for research remains “undiminished.” More hard-nosed researcher-practitioners like Campbell would certainly help.