Have you thought much about how a company treats its gay employees, customers, and investors? It's an issue important to many in America, and it can have an impact on a firm's bottom line. According to Packaged Facts' market research, the gay and lesbian population in America tops 15 million, with purchasing power of more than $650 billion. 

The Human Rights Campaign (HRC) in Washington, D.C., monitors how gay, lesbian, bisexual and transgender (GLBT) people are treated in corporate America. Its annual Corporate Equality Index (CEI) has been available for six years now. The 2008 report awarded 195 American corporations the top score of 100, up a whopping 41% increase over the previous year's results. The index sets out to measure the respect companies have for GLBT employees, consumers, and investors, looking at factors such as parity in retirement and health-insurance benefits, diversity training, and job protection.

Here are some interesting stats:

  • There were 519 companies rated, with an average score of 81.
  • Three companies earned ratings of 0: ExxonMobil, supermarket firm Meijer, and the consultancy Perot Systems. According to the HRC, "None of these employers have taken positive steps toward GLBT employees, and in two cases -- ExxonMobil and Perot Systems -- they have rescinded GLBT-inclusive policies."
  • Wal-Mart saw its score fall from 65 to 40, partly because of ending its corporate-level funding for GLBT groups.
  • Entergy (NYSE:ETR) saw its score jump from 13 to 88. The company had stopped eligibility for domestic-partner benefits at a nuclear power plant it acquired in 2003, but it now offers such benefits companywide.
  • Four other companies ran up huge improvements of at least 50 points in their scores: Alltel, Automatic Data Processing (NYSE:ADP), J.C. Penney (NYSE:JCP), and KB Home (NYSE:KBH).
  • Those earning scores of 100 include Xerox (NYSE:XRX), Cisco Systems (NASDAQ:CSCO), and Sun Microsystems (NASDAQ:JAVA).

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Longtime Fool contributor Selena Maranjian owns shares of Wal-Mart and has coveted Xerox copiers since childhood. Wal-Mart is a Motley Fool Inside Value recommendation. Try any of our investing services free for 30 days. The Motley Fool is Fools writing for Fools.