Each weekday, 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. Embotelladora Andina ( AKO.A) engages in the production and distribution of Coca-Cola beverages in Chile, Brazil and Argentina. It has been upgraded to buy from hold. The company's revenue grew by 42.3% in the second quarter of 2007 compared with the same period last year, while net income increased by 66.78% in the same timeframe. An earnings increase of 58.33% in the second quarter continued a pattern of EPS growth over the past two years. Its other strengths include a notable return on equity and a stock price that has increased by 30.82% over the past 12 months. Embotelladora Andina had been rated a hold since June 2007. Waste management company Allied Waste Industries ( AW) has been upgraded to buy from hold. The rating is driven in part by the company's long-term strategy to improve profitability, which includes an agreement to sell certain solid waste landfill and collection assets. Allied Waste also has enacted several cost-reduction programs to lower expenses, and a de-leveraging strategy to reduce debt. The company has a robust pipeline of alternative energy projects to further enhance cost-effectiveness by offsetting the use of oil and natural gas. The company posted 2.3% top-line growth in the second quarter, driven by growth across all business segments. Allied Waste had been rated a hold since August 2005.