Mike and Jeremy Siegel, economics professor at the Wharton School of the University of Pennsylvania and author of The Future for Investors, debated the future economic and social impacts of the retirement of the baby boomers at the 9th annual Milken Institute Global Conference. Siegel argued that aging Americans will have to work longer than they expect, and that financial markets may not perform as well as needed because there are not enough people to buy the assets baby boomers hope to sell. Mike countered that Americans will lead longer healthier lives that allow them to enjoy working longer, and that growing middle classes and new financial technologies in developing countries will generate plenty of buyers to sustain financial markets. Read more at BusinessWeek Online.