There's a 40% chance of a recession within the next three to six months, according to some of the country's leading economists, including Joshua Feinman, chief economist at Deutsche Asset Management, New York. This prediction is based on plummeting consumer confidence levels, as tracked by The Conference Board, New York, as well as increases in mass layoffs and unemployment, as tracked by the Bureau of Labor Statistics. (Mass layoffs are those affecting 50 or more employees.) At press time, consumer confidence was at its lowest level since 1996, according to The Conference Board. "We're seeing [economic] mechanisms now that transform small setbacks into large ones," explains Ed McKelvey, vice president and senior economist for Goldman Sachs, New York. Other observers, including economists surveyed by Blue Chip Economic Indicators, Alexandria, Va., predict that this year's economy will