The Ethisphere Institute has named Waste Management to its 2011 World’s Most Ethical Companies list. Waste Management was included on the list for the fourth year in a row.

A total of 110 companies made the list. Other companies on the list include Adidas, American Express, eBay, Ford Motor Co., PepsiCo and Xerox.

“As companies strive to maintain a competitive advantage, good ethics translate into better business, and better business means better bottom lines,” said Alex Brigham, executive director of the Ethisphere Institute, in a statement. “Waste Management recognizes the important role that principled practices play in brand reputation, which ultimately is the most valuable asset for a corporation.”

According to a Waste Management press release, the Ethisphere Institute is “a think-tank dedicated to the creation, advancement and sharing of best practices in business ethics, corporate social responsibility, anti-corruption and sustainability.” The organization compiles the list in part by reviewing a company’s code of ethics, examining litigation and regulatory violation histories, and studying a company’s investment in sustainable business practices.