Many pro-Brexit Brits are taken with the idea that the U.K. doesn’t need to belong to a large bloc any more than its tiny former colony Singapore does. The Southeast Asian city-state, they argue, has flourished by lowering taxes and opening up its economy to trade and investment, and so can a post-Europe Britain. Those excited about the prospects for “Singapore-on-Thames,” though, might want to take a closer look at how Singapore itself works. Or doesn’t.

It is true that the tropical port has thrived on trade since before Sir Stamford Raffles landed there 200 years ago. British colonizers encouraged free flows of capital, goods and labor, which integrated the island into the region’s colonial-plantation export economy.

Singapore’s post-independence leader Lee Kuan Yew also saw the virtue in positioning his country within global trade flows. In recent years, even as a backlash against globalization has swept the West, Singapore has been an avid joiner of regional and bilateral free-trade pacts, including most recently the Comprehensive and Progressive Trans-Pacific Partnership and a free-trade agreement with the European Union.

Several other conditions have been critical to Singapore’s growth, though. And many of them won’t be so attractive to passionate Brexiters.

The state, for instance, plays an exceptionally heavy role in Singapore’s economy and society. Over 80 percent of the population lives in public housing, while a Central Provident Fund requires employees to park nearly 40 percent of their salaries into savings (the money can be used on housing and healthcare). In industrial policy, the government oversees a plethora of schemes targeting mostly off-budget public funding to particular sectors such as biopharma and aerospace, as well as activities such as R&D and skills training. Government-linked companies, whose controlling shareholder is the sovereign wealth fund Temasek Holdings Pte. Ltd., are the dominant players in transport, communications, real estate and media, and account for a significant share of total stock-market capitalization.

The state’s dominance makes negotiating free-trade agreements much easier than it would be in a post-Brexit U.K. The ruling People’s Action Party has commanded an overwhelming majority in Parliament since independence and never loses a vote. Local labor and domestic capitalists are relatively weak, and the country has no agricultural sector to protect. Internationally, Singapore’s small size, openness and longstanding friendliness to foreign business mean it poses no threat to domestic interests in partner countries, while its strategic geographical location makes it an attractive intermediary for entry into a much larger regional market. It will be much harder for the U.K. to negotiate similar pacts, especially if it can’t serve as a gateway to the EU.

More importantly, given its tiny population, Singapore’s growth has depended crucially on massive immigration—one of the fears that spurred the Brexit vote. Non-residents accounted for only 3.2 percent of Singapore’s labor force in 1970. By 2000, the share had risen to over 28 percent and now tops 38 percent. Following a backlash in 2011, which handed the PAP its worst electoral showing ever, the government has brought down the annual increase in foreign labor from 21 percent in 2008 to around 1 percent. But it’s still growing.

Moreover, Singapore has been an austerity lover’s dream, running budget surpluses of over five percent of GDP nearly every year since 1990. Combined with high savings rates (35 percent to 53 percent of GDP since 1981), that’s translated into persistently large current-account surpluses that have exceeded 10 percent of GDP since 1991 and 20 percent since 2005. These surpluses yield foreign-exchange reserves that are invested outside the country by GIC Pte. Ltd., the other sovereign wealth fund. Exporting capital restrains currency appreciation and keeps Singaporean exports competitive. In a more substantial, less-open economy such as the U.K., such policies would be considered “mercantilist.”

The final irony is that Singapore may not be as clear-cut a success story as Brexiters imagine. A growth model based on large inputs of capital and imported labor has delivered poor productivity growth. Annual total factor productivity growth fell from 2 percent in the 1980s to 1.4 percent in the 1990s and 0.5 percent in the 2000s, when employment contributed 75 percent to (now lower) GDP growth, versus 31 percent in the 1970s.

At the same time, like the U.K. and many other high-income countries, Singapore has experienced relative wage stagnation and rising income inequality. The share of wages and consumption in GDP is very low, with the latter ranging between 35 and 49 percent of GDP every year since 1981. This means that consumer welfare is much lower than Singapore’s high per capita income would suggest, and lower than in countries with similar income levels.

Even Singapore’s liberal trade and investment policies are unlikely to yield the same growth dividends they did in the past, given the slowdown in globalization and the rise of market, technological and political forces that favor increased regionalization if not nationalization of production and distribution of goods and services. Global capital flows in particular face increased restrictions meant to combat tax-dodging, while countries everywhere are far less tolerant of industrial policies that can be cast as “illegal” state subsidies.

It’s not clear that Singapore’s past national development strategy will continue to be viable for Singapore itself. Singapore-on-the-Thames shouldn’t count on following the same model.