Will Love Win? A Prediction on the Future of Same-Sex Marriage in Southeast Asia

Briggs Murray

On January 23, 2025, at a time when the biting cold would entice most Americans to huddle around their crackling fireplaces, on the other side of the world something remarkable was underway.  In the sweltering tropical air of Bangkok, Thailand, over 100 couples withstood the discomforting heat of midday as they proudly filed into a shopping mall.  This mall, the Siam Paragon, appeared quite ordinary on any normal day – its glass facade and golden trimming camouflaged the building amidst Bangkok’s glitzy urban jungle.  Yet today was not a normal day.  Today, the Siam Paragon was extraordinary.  Today, those couples were not going shopping: they were getting married, en masse.  After decades of tireless grassroots activism, Thailand’s parliament finally passed a landmark same-sex marriage law, promulgated through the blessing of King Vajiralongkorn.  

Thailand is the first country in Southeast Asia to have recognized marriage equality, and only the third nation in broader Asia to have done so, after Taiwan in 2019 and Nepal in 2023.  Thais like Ann Chumaporn, co-founder of Bangkok Pride, are keenly aware of the historic nature of this bill.  Chumaporn told the BBC that, aside from guaranteeing fundamental rights of equality among its citizens, Thailand is “also writing a page in history ... that tells us that love never set a condition of who we were born to be.”  Yet, when considering Southeast Asian history at large, will same-sex equality be relegated to only this one pithy page?  Or will other countries soon follow in Thailand’s footsteps, creating a lengthier chapter?  

To determine a prediction of the future, it’s worth considering the ASEAN political bloc as an approximation of a loose federalist governmental system.  ASEAN – the Association of Southeast Asian Nations – is a cooperative intergovernmental organization whose member states are Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Singapore, Thailand, Vietnam, and the Philippines.  These states collaborate to solve prominent regional issues through effective decision-making, much in the same way a federal government might attempt to remedy challenges beleaguering multiple constituent states.  Now, it is important to note that a core ASEAN principle upholds and affirms each member state’s sovereignty, and therefore unlike a federal government there is no way to legally compel adherence to a preferred policy within one or more constituent states.  However, for the purposes of this article, what is important is the de facto affiliation – that Thailand shares an affiliative bond to Vietnam through ASEAN much in the same way California might be bonded to Colorado or Arizona under the American federalist system.  

Under this collaborative framework – where each state is influenced by its affiliates, but not compelled – it is worthwhile to examine how policies are generally diffused across state boundaries in the United States.  A principal way to model this policy process applies innovation diffusion theory, pioneered by Dr. Everett M. Rogers.  He defines policy diffusion as “the process by which an innovation is communicated through certain channels over time among the members of a social system.”  “Innovation” in this sense refers to a specific policy not realized hitherto, and the “social system” can be identified as either a comparatively centralized (i.e. United States) or decentralized (i.e. ASEAN) governance structure.  Interestingly, Rogers theorizes that the adoption of a new policy innovation follows a unimodal, normally distributed bell curve, graphically depicted below.  The distribution is separated into categories to quantify who adopts the policy, and at what time relative to other affiliates.  

A graphical conceptualization of Rogers’s diffusion of innovations theory. 

Of course, Rogers’s model of diffusion is not universally true – if a policy is innovated once, it is not predestined to be enacted elsewhere too.  Rather, there are three reasons that offer indications of a policy’s emulation likelihood, as outlined by Frances Stokes Berry and William D. Berry in their chapter “Innovation and Diffusion Models in Policy Research” for the book Theories of the Policy Process.  First and most obviously, the innovator’s policy must be convincingly successful.  Whether that be measured politically, economically, socially, or culturally, the policy must have some tangible advantage to incentivize others to replicate it.  Second, affiliated states are in social competition with one another.  In order to avoid being disparaged, there is immense pressure to conform to the collective’s accepted standards.  Lastly, and importantly, governmental officials may be pressured by public activism.  Citizens of a country might look at an affiliate nation’s policy and ask its government: “why don’t we have this, too?”  Seeing a desirable policy enacted elsewhere encourages civil society to push for that same policy on the homefront.  The reasons above established, now let’s return to the central question: Will Thailand’s legalization of same-sex marriage create a policy diffusion chain reaction in Southeast Asia?

Yes, probably.  But it will take time.  Marriage equality will likely proceed gradually and incrementally across the region, and Berry and Berry’s rationales explain why.  Reason number two can be immediately eliminated as a change agent.  Even though ASEAN does profess a goal of accelerating “social progress and cultural development in the region,” LGBTQ rights are currently nowhere on the organization’s agenda, largely due to virulent hostility by powerful Islamic sects in Brunei, Indonesia, and Malaysia.  As such, the collective’s standards have not tipped in favor of this social policy.  

Reason number three is also unlikely to produce change because even though evidence shows public support for same-sex equality in Indochina, the preponderance of ASEAN nations have restrictions against lobbying efforts and peaceful protests.  A 2023 Pew Research Center survey tabulated support for same-sex marriage at 65% in Vietnam, 57% in Cambodia, and 45% in Singapore.  For reference, that same poll recorded 60% favorability in Thailand.  Polls have equally suggested surging public support for the measure in the Philippines.  Yet in these nations, it is very difficult to translate public support into action as a result of political repression.  According to the 2025 annual report by Freedom House, a US-based non-governmental organization dedicated to tracking democracy and freedom across the world, not a single ASEAN nation qualifies as “free.”  Four – Indonesia, Malaysia, Singapore, and the Philippines – were classified as “partly free.”  The other six, including Thailand, were given the lowest score: “not free.”  As evidenced by Thailand, civil society activists can still certainly exert a demonstrable pressure on the government, but its full effects are impeded by these restrictions.

Perhaps the best argument finds itself in reason number one – that marriage equality is simply a smart economic policy.  As a result of LGBT-friendly policies, Thailand’s tourism industry is now uniquely positioned in Southeast Asia to benefit from foreign LGBT travelers.  BBC News reports that “the country is seen as a safe and welcoming destination for LGBT holiday-makers” especially from Europe and North America, who are often willing to spend big bucks on their travels.  It should come as no surprise, then, that the Tourism Authority of Thailand anticipates an unprecedented 40 million foreign vacationers in 2025, raising year-over-year tourism revenue by a projected 7.5%.  BBC News also points out that “growing numbers of same-sex couples from other Asian countries” are migrating to Thailand to profit from “nearly all the rights and protections given to heterosexual couples” in marrying and starting a family.  Lastly, the LGBT film industry also contributes to Thailand’s overall economic growth.  The economic output from the same-sex television series subgenre is growing at a blistering 17% annually.  Time Magazine has even branded the “boys love” genre depicting same-sex male relationships “Thailand’s soft power, doing for the Southeast Asian nation’s global image what the yoga boom has done for India or K-pop for South Korea.”  

In the coming years, as the economic benefits of Thailand’s LGBT inclusivity become ever clearer, it is probable that other ASEAN nations will seek to emulate a portion of Thai success through reforms of their own.  While the prospective future of same-sex marriage in Southeast Asia is uncertain, it may be helpful to reflect on the United States’ own path towards equality.  Less than two decades ago, Massachusetts became the first state in the country to legalize equal marriage rights.  They consequently became the policy innovator.  For a while, it seemed as if nationwide same-sex equality was a pie-in-the-sky dream, quixotically impossible to ever practically accomplish.  Then, four years later, Connecticut joined the ranks, the first in a succession of early adopters.  By 2013, influenced and emboldened by their affiliate neighbors, state after state began passing their own legislation.  It seemed a pure reflection of Rogers’ theory on policy diffusion, substantiated by Berry and Berry’s three rationales.

A graph applying Rogers’s innovation diffusion theory to U.S. state adoption of same-sex marriage equality. *Note: Late majority ends at 70% adoption rate here instead of Rogers’ theorized ~84% to reflect the fact that 30% of states did not adopt voluntarily, but were compelled to act by the Supreme Court decision in Obergefell v. Hodges (2015).

Upon the ratification of Massachusetts’ 2004 law, if you were to tell a random passerby that in just eleven years’ time same-sex marriage would be the law of the land, they would have been far more likely to scoff at you than to nod in accordance.  In Southeast Asia, all indications assuredly point to an elongated time horizon, but that does not indicate a failure to diffuse.  Thailand is the regional innovator; which nation will follow suit and at which time is a guessing game, but the point rests that it’s likely to happen.  The page in history referred to by Ann Chumaporn will conceivably be the first in a succession of many. 

Celebrating at the mass wedding event in Bangkok was Rungtiwa Thangkanopast, newly married to Phanlavee Chongtangsattam.  She was one of many to speak to the New York Times on Siam Paragon’s extraordinary day.  “I am delighted and excited because we have been waiting for this day for a very long time.  For 20 years, we have loved each other and have had to hide from society’s disapproval. But now we can stand proudly.”  Let us hope that a newlywed in Vietnam or Singapore or the Philippines will not have to wait twenty more to say the same.