Exhibit 10 Margarita Torres: Sustainable Growth Model for Costco (1997 - 2001) Sustainable Growth Model (millions) 2001 2000 19991 1998 1997 Net Income 602 631 515 460 312 Owner's Equity 4,240 3,532 2,966 2,468 NA Return on Equity (ROE) 14.2% 17.9% 17.4% 18.6% NA Dividend 0 0 Net Income 602 631 515 460 312 Dividend Payout 0.0% 0.0% 0.0% 0.0% 0.0% Earnings Retention Ratio 100% 100% 100% 100% 100% Net Income 602 631 515 460 312 Assets 8,634 7,505 6,260 5.476 NA Return on Assets (ROA) 7.0% 8.4% 8.2% 8.4% NA Assets 8,634 7,505 6,260 5,476 NA Owner's Equity 4,240 3,532 2,966 2,468 NA Financial Leverage 2.04 2.12 2.11 2.22 NA Net Income 502 631 515 460 312 Sales 34,797 32,164 27,456 24,270 21,874 Net Margin (Return on Sales) 1.73% 1.96% 1.88% 1.90% 1.43% Sales 34,797 32,164 27,456 24,270 21,874 Assets 8,634 7,505 5,260 5,476 NA Asset Turnover 4.03 4.29 4.39 4.43 NA Pretax Income (continuing operations) 1,003 1,052 859 766 520 Sales 34,797 32,164 27,456 24,270 21,874 Pretax Return on Sales 2.88% 3.27% 3.13% 3.16% 2.38% Pretax Income (continuing operations) 1,003 1,052 859 766 520 Taxes 401 421 344 306 208 Tax Rate 40.0% 40.0% 40.0% 39.9% 40.0% Tax Effect (1 - Tax Rate) 60.0% 60.0% 60.0% 60.1% 60.0%