[Author Affiliation]Dennis Coates, Department of Economics, UMBC, 1000 Hilltop Circle, Baltimore, MD 21250, USA; coates@umbc.edu; corresponding authorJac C Heckelman, Wake Forest University, 110 Carswell Hall, Winston-Salem, NC 27109, USA; Jac_C_Heckelman@mta.wfu.eduTwenty-five years ago, Mancur Olson published Rise and Decline of Nations . In the same year, he also served as president of the Southern Economic Association. importance of Rise and Decline has been acknowledged in various venues. American Political Science Association awarded Olson the Gladys M. Kammerer award for the best political science publication in the field of U.S. national policy. A series of symposia centered on Rise and Decline became special issues of International Studies Quarterly (1983), Scandinavian Political Studies (1986), and Public Choice (1987). book has subsequently been translated into 11 languages, and its interdisciplinary nature is evident by the continued research on its themes from economists, political scientists, historians, and sociologists, with over 1500 citations listed in the Social Science Citation Index .To commemorate the 25th anniversary of the publication of Rise and Decline of Nations and Olson's related Southern Economic Association presidential address, and to determine how well they have stood the test of time, we arranged with Laura Razzolini, the editor of the Southern Economic Journal (SEJ), for a symposium to appear in the SEJ. A session was organized for the 2006 meeting of the Southern Economic Association in conjunction with the symposium. Two papers presented at that session, and two others developed subsequently, compose this symposium.The papers we collected take a new look at the central thesis of Rise and Decline . That thesis, which Olson referred to as institutional sclerosis , is interest groups develop over time in stable societies, compete over their share of the national income, and, in the process of competing with one another, induce slower growth in income. four papers included in this symposium extend Olson's theory in new directions. Each author's contribution honors Mancur Olson's ideas by building on them--standing on the shoulders of giants, as Olson would say--whereas in this case, the giant is Olson himself. That is not to say that each paper takes Olson's theory or related hypotheses as a fact or as the final word in understanding the relationship between interest groups and economic growth. Indeed, Olson's ideas are seen for their strengths, as well as weaknesses, in these papers.Mancur Olson, in fact, would claim that assessing the strengths and weaknesses of a theory embodies the scientific process. Indeed, as J. Barkley Rosser, Jr., argues in the first paper of the symposium, Olson's own understanding of the role of interest groups in creating economic stagnation, and how the problem may be solved, changed over time. Interestingly, Rosser finds evidence of the evolution of Olson's ideas manifest in his presidential address to the Southern Economic Association in November 1982. address was published in 1983 under the title The South Will Fall Again: South as Leader and Laggard in Economic Growth. Rosser argues that Olson's final works on good governance, such as the posthumously published Power and Prosperity , saw him come full circle on the interaction between interest groups and government policy.In the second paper, Jac C. Heckelman assesses the literature that has tested the model described in Rise and Decline . Evaluating the general support or rejection of the model from 50 studies published in economics and political science journals or in books and collected volumes, Heckelman concludes that the general finding in the literature supports the hypothesis of institutional sclerosis. 50 studies include works authored by Americans and Europeans, employing either regression analysis or case studies of various countries. …