U.S. retail sales for November and December should rise 5.7% over last year's figures, to $217.4 billion. That's the forecast from the National Retail Federation (NRF), which, if accurate, would make this year's holiday showing the best since 1999, when general merchandise sales in the two-month period climbed 8.2%. Last year at this time NRF predicted that holiday sales would grow 4%. They actually increased 2.2%. "After several strong months of retail sales growth, it seems clear that the economy is picking up momentum just in time for the holidays," says NRF chief economist Rosalind Wells. "Retail sales gains for the 2003 holiday season will be far better than the meager increases retailers experienced a year ago." Wells cites a variety of factors for the optimistic forecast, including low interest rates, low inflation, rising equity markets, and mounting consumer confidence. Also