J. Scott Armstrong (born March 26, 1937) is an author, forecasting and marketing expert, and a professor of marketing at the Wharton School of the University of Pennsylvania. He also serves as a Policy Expert at the Heartland Institute, a conservative and libertarian public policy think tank. In line with the Heartland institute's climate change denial, he has published articles stating that scientists whose research contributed to the scientific consensus on climate change did not apply the forecasting principles used in economics, a demand which was rejected by those scientists.