Each business day, TheStreet.com Ratings updates its ratings on the stocks it covers. The proprietary ratings model projects a stock's total return potential over a 12-month period, including both price appreciation and dividends. Buy, hold or sell ratings designate how the Ratings group expects these stocks to perform against a general benchmark of the equities market and interest rates.While the ratings model is quantitative, it uses both subjective and objective elements. For instance, subjective elements include expected equities market returns, future interest rates, implied industry outlook and company earnings forecasts. Objective elements include volatility of past operating revenue, financial strength and company cash flows. Allied Waste Industries ( AW) provides waste collection, transfer, recycling and disposal services in the U.S. and Puerto Rico. It has been downgraded to hold from buy. The company's revenue grew by 2.0% in the third quarter compared with the same period last year, outpacing the industry average of 0.6%. Allied Waste also displays expanding profit margins and good cash flow from operations. However, its third-quarter earnings fell by 11.77% to 15 cents per share from 17 cents a share in the same period last year, and the company has shown generally poor debt management. Its stock price has fallen 14.96% in the last 12 months, and despite the decline, is still selling for more than most others in its industry. Allied Waste had been rated a buy since August 2007.