UPDATED: One of our contacts at GM wrote in with a couple of important clarifications. See the note below.

The Human Rights Campaign is America's largest advocacy group for lesbian, gay, bisexual, and transgender rights, and for ten years, the organization has been ranking companies on their LGBT-friendliness. This year, three automakers scored a perfect 100 on the HRC's annual Corporate Equality Index, including two of Detroit's Big Three.

What's the Corporate Equality Index?

According to the HRC's website, the Corporate Equality Index "provides an in-depth analysis and rating of large U.S. employers and their policies and practices pertinent to lesbian, gay, bisexual and transgender employees." Each company is scored according to a nine-item set of criteria. Points are awarded for policies that prohibit discrimination on the basis of sexual orientation and gender identity, and points are deducted for any "large-scale official or public anti-LGBT blemish on their recent records" (like the one Target suffered in 2010).

We're happy to announce that three automotive companies scored a perfect 100 on the HRC's 2012 Corporate Equality Index: Chrysler, Ford, and Toyota. Volkswagen landed a very respectable 90 (improving some internal HR programs would bring VW up to a 100), Subaru received an 85 (though to land a perfect score, it needs to offer soft benefits like bereavement leave to domestic partners as well as transgender-inclusive health coverage), and General Motors also scored an 85 (though strangely, GM doesn't offer health and medical insurance for domestic partners*).

Much further down the list, we find Nissan, which -- like most Fortune 500 companies -- has a non-discrimination policy, and which also offers health insurance for LGBT couples, but doesn't do much else, giving it a lackluster score of 30. (In fairness, Nissan did announce opposition to a bill that would erase LGBT protections in Tennessee, where its U.S. headquarters are located. Unfortunately, it made that announcement after the bill had been passed and signed into law. Oops.)

Scroll a little more, and we find Penske Automotive, one of only three companies in the auto sector to score a perfect zero.

Who's not on the list?

There are plenty of automakers that aren't ranked on the HRC's 2012 Corporate Equality Index -- major companies like Honda, Hyundai, Mazda, and Mercedes-Benz. Why didn't they make the cut? According to page 10 of the document, there are three types of companies included on the Index:

1. Fortune magazine’s 1,000 largest publicly traded businesses (2010 Fortune 1000)

2. American Lawyermagazine’s top 200 revenue-grossing law firms (2010 AmLaw 200).

3. Additionally, any private-sector, for-profit employer with 500 or more full-time U.S. employees can request to participate

The missing automakers don't have a large-enough business presence in the U.S. to make the first cut, and apparently, they didn't apply to be included as per item #3. However, a quick look at Gaywheels.com's list of gay-friendly automakers reveals that only four auto brands -- Hyundai, Kia, Porsche, and Suzuki -- fail to provide at least a non-discrimination policy for LGBT employees. (Full disclosure: I double as the webmaster for Gaywheels.com.)

Why does it matter?

Social conservatives argue that offering benefits for LGBT employees makes businesses less competitive by creating a protected class of employee. That's a much more business-like argument than simply citing religious scripture, and it often plays well with state and city officials.

However, LGBT advocates insist that companies that don't offer at least a non-discrimination policy are shooting themselves in the foot. Since discrimination on the basis of sexual orientation is perfectly legal in 29 states, LGBT workers often look for companies with policies that explicitly prohibit such discrimination. Without that protection, advocates argue, LGBT employees will often choose to work someplace else.

Both sides use data to support their points, but the LGBT advocates are clearly winning the argument: 99% of the 1,117 companies rated in the HRC's 2012 Corporate Equality Index have non-discrimination policies in place. Those policies may not be the sole reason that these companies are the biggest in the U.S. -- but then again, they probably didn't hurt, either.

In the highly competitive automotive industry, having a talented workforce is key to success, and employers have come to realize that diversity is means of attracting talent. In this case, it's not about creating quotas, it's simply about making workers feel comfortable, appreciated, and happy -- because as we've seen time and again, happy workers are productive workers. Chrysler, Ford, Toyota, Volkswagen, Subaru, and GM seem to understand that. We'll see how they stack up against the competition down the line.

To download the HRC's 2012 Corporate Equality Index as a PDF or review it online, click here.

* UPDATE, courtesy of Joe LaMuraglia, General Motors' LGBT Liaison for Communications: "GM absolutely offers health and medical insurance for same-sex domestic partners and was among the first automakers to do so in 2000. We did drop from 100 to 85 this year on the HRC CEI, and it seems the reason is that HRC may have changed their criteria for a perfect score. GM currently does not offer health and medical insurance for dependents of same-sex partners who are not tax-dependent. So, for example, if you had a child from a previous marriage and your ex has listed that child as a dependent on their taxes, then they are not currently eligible for health and medical insurance coverage under the current program. GM is currently reviewing this policy, and while it has not been changed as of today, it is under consideration."