GPI vs. GSP (IMAGE) University of Maryland Caption "In 2000, the classic economic measure showed Maryland more than 50 percent wealthier than we actually were, as measured by the greener GPI." says University of Maryland researcher Matthias Ruth. Credit University of Maryland and Maryland Department of Natural Resources Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.