Technology requirements for population and economic growth

Summary form only given. This paper first demonstrates that policy conclusions based on the World3 model are robust to correction for key economic criticisms and to sensitivity analysis of model parameters. Changes to the model are introduced, making aggregate production a function of population as well as industrial capital, more realistically allocating industrial output to economic sectors, and allowing for irreversibility in the improvement of labor productivity. Resource-related criticisms are addressed by pointing out that resource constraints can be relaxed without affecting the nature of the conclusions, and technology-related concerns are addressed later through technological benchmark analyses. Next, the paper introduces the concept of technology benchmarks. Such benchmarks are estimated lower bounds to technology levels needed at each point in time to support a given growth path of world population and industry. Growth must be supported in terms of food, resource, and environmental requirements of world population and industry. The paper argues that, given the model´s detailed use of relevant scientific data and literature, the World3 model is an appropriate starting point to develop estimates of technology requirements. Results are presented as curves showing tradeoffs between technologies to enhance crop yields and to reduce pollutant impacts, and as a figure for requisite improvements in resource efficiency