I am an economic historian mainly working on growth, energy and environmental issues over several centuries. My work has involved the construction of new time series of energy and greenhouse gases as well as benchmark estimates. I have set an example for how to conduct historical studies in the field by my Swedish case study, which has been followed up by several other scholars for other European countries, within a network (LEG) that I have coordinated since 2003. The role of technology (innovations) and structural change play an important role in the analyses of the data. I have addressed both energy's role in productivity and growth and its effect on the environment in the form of greenhouse gases. I have also addressed broader climate change issues by examining historical emissions from agriculture and forestry. My most significant contributions in this area are:
- Showing that in many cases in the long run (200 years) energy intensity declines, rather than following an inverted U shape path as many have suggested. This is due to the strong effect on emissions from the transitions from an informal economy to a formal economy and from technological change, which have counteracted structural change.
- Killing the myth that the transition to a service economy has reduced environmental impacts. Rather than being caused by an increase in the relative size of services in the economy, the energy intensity decline since the mid1970s is caused by the growth of information and communication technologies (ICT), affecting the structure of manufacturing industry as well as increasing the efficiency in the traditional branches of industry.
- Demonstrating that declines in energy intensity were not caused by international trade allowing the offshoring of pollution intensive activities.
- Showing that emissions from forestry and agriculture can be very important compared to energy emissions for historical records of greenhouse gas emissions.
- Showing that there is more substitutability between capital and energy in the long run than between capital and useful work. However, since the mid1970s ICT capital has increased in importance relative to useful work.
A second strand of my research deals with R&D, innovation and growth. I have in a couple of publications questioned the so called "Swedish paradox" (high R&D and low growth). Most importantly I have shown that:
- The gap between R&D and economic growth only exist for fast-growing sectors of the Swedish economy. This implies diminishing returns to R&D rather than a malfunctioning innovation system.