Three billion people will be added to the world ' s population over the next 50 years and 2.8 billion people today already live on less than $2 a day-almost all in developing countries. Ensuring these people have access to productive work and a better quality of life is the core development...

"The authors develop an endogenous growth model that combines structural change with repeated product improvement. That is, the technologies in one sector of the model become not only increasingly capital-intensive, but also progressively productive over time. Application of the basic model to...