The predominant role of investment. In 2005 Jorgenson traced the American growth resurgence to its sources in individual industries in his book, Information Technology and the American Growth Resurgence, co-authored with Mun S. Ho and Kevin J. Stiroh. This book employed the framework originated by Jorgenson, Frank M. Gollop, and Barbara M. Fraumeni, but added detailed information about investments in information technology equipment and software. Jorgenson and his co-authors demonstrated that input growth, due to investments in human and non-human capital, was the source of more than 80 percent of U.S. economic growth over the past half century, while growth in total factor productivity accounted for only 20 percent. Jorgenson and Khuong Vu (2005) established similar results for the world economy.