For all the scandalous and depressing behavior in corporate America that regularly comes to light, there are good changes, too. Many companies are now increasing workplace equality by offering gay- and lesbian-friendly policies and benefits, such as parity in retirement and health-insurance benefits, diversity training, and job protection.

The Human Rights Campaign (HRC) has been monitoring these changes, rating hundreds of companies each year on their performance in this area. HRC's 2010 "Corporate Equality Index" gave perfect ratings to 305 of 590 companies (that's 52%), up from just 260 with top scores last year, and 195 the year before. Here are some of the companies that improved their ratings to a perfect 100 this time around:

  • Procter & Gamble (NYSE:PG)
  • Alcoa (NYSE:AA)
  • Costco (NASDAQ:COST)
  • General Mills (NYSE:GIS)
  • Monsanto (NYSE:MON)

ExxonMobil and The Laclede Group were rated zero; ExxonMobil earned its demerits for not yielding to shareholder requests to reinstate policies and benefits that were in place at Mobil when it merged with Exxon.

Increased diversity, increased performance?
This trend toward greater acceptance should be welcome to investors chasing high-performing companies that can deliver great results. These high-rating companies are likely to curry the favor of gay consumers, who make up more than 6% of the population. And according to research by Harris Interactive, gay consumers' purchasing power topped $690 billion in 2007 -- a market definitely worth pursuing. Best Buy (NYSE:BBY), has used focus groups and other initiatives to research ways to attract more gay consumers, and car companies such as General Motors and Ford have been supporting gay organizations and events. 

Gay-friendliness can also be a competitive advantage, helping companies attract and retain talent. As CarMax (NYSE:KMX) CEO Tom Folliard said, "We hire associates with diverse and unique backgrounds and understand the competitive advantage they bring to our organization." And Seth Zachary of the Paul, Hastings, Janofsky & Walker law firm said that its diverse workforce "gives us a competitive edge and the ability to deliver the best possible service to our clients worldwide."

As the financial incentives of greater equality become clearer, it's likely that next year, many more companies will have made the necessary changes to earn perfect scores.

Longtime Fool contributor Selena Maranjian owns shares of Costco and Procter & Gamble. Best Buy and Costco are Motley Fool Stock Advisor recommendations. Best Buy and Costco are also Motley Fool Inside Value selections. Procter & Gamble is a Motley Fool Income Investor recommendation. The Fool owns shares of Procter & Gamble, Best Buy, and Costco. Try any of our investing newsletters free for 30 days. The Motley Fool is Fools writing for Fools.