When California briefly offered same-sex couples a real choice between marriage and domestic partnership in 2013, couples chose marriage over the alternative by more than 22 to 1. That finding comes from Stanford sociologist Michael Rosenfeld’s analysis of 48,310 same-sex domestic partnerships filed with the California Secretary of State between 2000 and 2020, published in the Journal of Marriage and Family and summarized in a PsyPost write-up of the findings. Domestic partnerships were built to give couples a lighter legal alternative to marriage, something with fewer strings and less formality. Given the option, same-sex couples overwhelmingly didn’t want lighter. They wanted marriage.
A Natural Experiment Nobody Planned
Rosenfeld’s research took advantage of an unusual window in California law. For years, domestic partnerships were the only legal option available to same-sex couples in the state, so their popularity said little about genuine preference; it was simply the only door open. Once the state legalized same-sex marriage in mid-2013, that changed, and couples suddenly faced an actual choice between two legally recognized paths. The years right after that shift function almost like a natural experiment: two options, one newly available, and a large enough sample of real couples making a real decision to draw conclusions from. The 22-to-1 ratio in favor of marriage measures what happened immediately after the change, when the appeal of the newly available option might have been expected to be strongest.
The Preference Held Up Over Time
What makes the finding more convincing than a one-time novelty effect is that the preference for marriage didn’t fade much as the initial excitement wore off. Looking at couples’ choices between 2016 and 2018, several years after marriage became available, Rosenfeld found the ratio had settled to around 13 to 1, still an overwhelming preference for marriage even once the immediate rush had passed. A separate, nationally representative survey Rosenfeld drew on, the 2022 How Couples Meet and Stay Together study, found marriage preferred by roughly three to one among its same-sex relationship respondents nationwide, reinforcing that the California pattern wasn’t a regional or timing quirk.
Why Couples Picked Marriage Anyway
The reasons couples gave, drawn from written explanations collected as part of the survey data, centered on practical advantages that domestic partnerships never fully matched. Marriage carries federal recognition and the tax and benefits treatment that comes with it, something domestic partnerships have never reliably offered even in states that created them. Marriage also travels; a couple married in California stays married if they move to another state, while domestic partnership status has historically been far less portable across state lines. And beyond the legal mechanics, couples described marriage as simply signifying a deeper level of commitment than a domestic partnership does, a distinction that mattered to people even when the practical legal differences between the two options were narrow.
What This Says About “Marriage-Lite” Alternatives
The finding lands as a pointed data point in a longer-running debate about whether alternatives to marriage, civil unions, domestic partnerships, registered partnerships, actually meet the same need marriage does once people have a real choice. Advocates for those alternatives have long argued they offer meaningful protection without requiring couples to buy into an institution some see as outdated or unnecessary. Rosenfeld’s data suggests that when the institution itself is finally accessible, most couples don’t experience it as unnecessary at all. They experience the alternative as the compromise it always was, something people used because marriage wasn’t available to them, not because it was ever what they actually wanted.
The Bigger Picture for Marriage Itself
Rosenfeld has framed this research as evidence for what he calls the enduring distinctiveness of marriage as an institution, a pattern he argues says something about marriage generally, well beyond the same-sex couples his data happened to track. For decades, part of the argument against extending marriage rights to same-sex couples rested on the idea that civil unions and domestic partnerships were an adequate substitute, separate but functionally equal. The data couples generated with their own choices says otherwise. People who had genuinely equivalent legal options in front of them consistently walked past the lighter one and chose the heavier commitment instead, which is a strange thing to see happen at scale if marriage and its alternatives were ever really interchangeable.
Two decades of legal experimentation with marriage alternatives produced a clear answer once same-sex couples got to choose freely: given the real thing, almost nobody picks the substitute.
