Select the correct words to complete this text: One key factor driving economic growth is the increase of , which means an increase in the value that each employed person creates per unit of his or her input. It can be driven by technological change and/or by improvements in skills and knowledge . Technological change refers to having better machines that allow fewer people to do work that used to require a greater number of people. Improvements in are things like acquiring new , allowing people to perform new jobs that they could not do before