Book excerpt: The Kiplinger Washington Letter, America's preeminent business forecasting publication, has an unmatched record of accuracy over its 75 years of publication, giving its readers early notice of high-impact trends in demographics, technology and government that would change the way America lives and does business. In 1989, when most analysts were warning of a grim decade ahead, Kiplinger dissented. In America in the Global '90s. Knight Kiplinger predicted America would set the world pace for economic success, with declining inflation and interest rates, soaring exports, a shrinking budget deficit, and a Dow of at least 6000 by the end of '99 (a forecast that sounded crazy just 18 months after the "87 crash. with the Dow a little over 2000).Now Knight Kiplinger broadens his lens to the century ahead. Will the 21st century be marked by fierce global competition and falling wages in manufacturing and farming, excessive population growth and famine in the developing nations, and declining living standards in the U.S. and other advanced nations? Or will accelerating growth in the Third World -- with the spread of technology, the empowerment of women and emergence of an immense new world middle class -- create unprecedented opportunities for American business? Kiplinger makes a persuasive case for the latter scenario, with many examples of how it will happen, and how U.S. business can profit.