Same-Sex Partnership Laws Reduce Syphilis Rates

The prevalence of the sexually transmitted infection syphilis has fallen by nearly a half in parts of continental Europe as a result of recently introduced national laws that allow for the legal recognition of same-sex partnerships.

That is the central finding of new research by Professor Thomas Dee, published in the July 2008 issue of The Economic Journal.

How might these laws have influenced the prevalence of sexually transmitted diseases such as syphilis? Professor Dee conjectures that:

''The legal recognition of same-sex partnerships may reduce the levels of sexual promiscuity among homosexuals by creating legal and financial incentives as well as social norms similar to those associated with heterosexual relationships.''

What's more, by reducing the social stigma of homosexuality, these laws could limit the transmission of sexually transmitted infections by discouraging furtive, high-risk sexual activity and the ''closeting'' of sexually active homosexuals in heterosexual relationships.

The study uses World Health Organization (WHO) data on European countries from 1980 to 2003. During this period, nine European nations – Denmark, Norway, Sweden, Iceland, Netherlands, France, Germany, Finland, and Belgium – introduced new laws that allowed same-sex couples to form legally recognised partnerships and, in some countries, marriages.

The wave of new laws legalising same-sex partnerships across Europe created legal rights (such as treatment as a couple for the purposes of inheritance tax), economic benefits (including joint tax assessment) and a nationwide social recognition similar to that available to married heterosexual couples. Most of these laws followed the
design of Denmark''s landmark ''registered partnership'' law introduced in 1989.

This study identifies the effect of same-sex partnership laws on syphilis rates by comparing the changes in countries following the introduction of these laws to the contemporaneous changes in neighbouring countries that did not adopt the laws.

Analysis of the WHO data indicates that same-sex partnership laws reduced syphilis rates by approximately 43%.
Syphilis is a particularly appropriate sexually transmitted infection for this analysis because it appears to be relatively common among homosexual men (unlike gonorrhoea) and because the detection of syphilis typically occurs soon after infection (unlike with HIV, the human immunodeficiency virus).

How might these results contribute to the debate over the legal status of same-sex relationships? Professor Dee comments:

''Any policy that can reduce syphilis rates is beneficial from a public health perspective, particularly because of the role that syphilis is thought to play in the transmission of HIV.''

''But for many observers, the broader social significance of this finding may be in what it suggests about how the legal recognition of same-sex partnerships influences the patterns of commitment in same-sex relationships and, possibly by extension, the overall social standing of marriage.''

''Forsaking All Others? The Effects of Same-Sex Partnership Laws on Risky Sex'' by Thomas Dee is published in the July 2008 issue of The Economic Journal.

Thomas Dee

associate professor of economics and director at Public Policy Program at Swarthmore College.