Global Trade Booms, but Headwinds Blow

A synchronous upturn across major economies is reviving hopes that a multiyear lull in global trade is finally reversing and will lift emerging markets that built their economies around exports.

In Asia, the world's factory floor, exports are up sharply, including gains of 18% from a year ago in South Korea, 12% in Singapore and 20% in Vietnam. Chinese exports are up 6%, a rebound from the past two years, when exports contracted.

But it may be too early to celebrate. Much of the export growth in Asia this year comes from a jolt of demand for semiconductors, partly to power smartphone launches like the iPhone X. That chip demand is expected to fade next year. Economists warn some of the recent gains look strong when compared with 2016, a weak year for global trade, but that year-over-year comparisons will become less favorable in 2018.

Headwinds facing global trade are still blowing. Washington is pressing ahead with challenges to its trading partners, including Korea and China. Indeed, rising trade tensions were evident at a Pacific Rim summit Friday, when President Donald Trump repudiated decades of U.S. support for multilateral trade liberalization in the region. Debt levels are growing across the world, including in China, which could constrain future consumption and investment.

Demographic trends may also make it harder for goods trade to accelerate, as aging populations in the developed world spend more on services like health care. Some Asian exporters have demographic challenges of their own, including shrinking pools of low-cost labor.

"We think it's not going to last," Trinh Nguyen, senior economist at Natixis, said of the recent strong export numbers for some countries. "I don't think trade is going to contract, but I think the growth rate is going to slow."

Of course, any new demand for exports is welcome in Asian countries that built their economic models around selling to the rest of the world.

Europe, a key trading partner for Asian economies, is finally emerging from its post-financial crisis hangover, fueling demand for everything from sneakers to electronics. In Japan, long-depressed consumption has risen steadily this year. U.S. growth has picked up in the nation's eighth year of expansion.

Buoyed by global growth, South Korea's gross domestic product expanded at the fastest pace in seven years last quarter and is expected to grow a healthy 3% this year. Singapore's economy grew at its fastest pace in more than three years last quarter, and the government says it expects growth to approach 3%, too.

Yet while 3% is considered solid growth for both countries today, it is slow compared with the 1980s and 1990s, when South Korea and Singapore regularly grew well above 10%. Even during the 2000s, both countries consistently notched 5% growth.

And while the World Trade Organization estimates global trade will grow 3.6% in 2017, that pales in comparison to the two decades leading up to the financial crisis, when annual trade grew at an average of about 6% a year.

"We're in the sweet spot of the global economy; this is the time when trade growth should be shooting up," said Michael O'Sullivan, chief investment officer of the international wealth management division at Credit Suisse, and co-author of a report titled "Getting Over Globalization."

Because some of the industries driving today's growth in Asia are so cyclical, the risk of a sharp swing looms.

The semiconductor market grew 17% this year but is expected to expand just 4% next year and even more slowly in 2019, as supply catches up with demand, according to the World Semiconductor Trade Statistics, a nonprofit that tracks industry data. East Asia makes roughly 70% of the world's semiconductors.

Gabriel Chou, the world chair of the WSTS and a project manager at Macronix, a Taiwanese semiconductor producer, said sales were up in the "double-digits" this year for his company, thanks in part to strong orders from the automotive industry.

Still, "we foresee this to be cyclical," he said.

Policy makers across Asia have been trying to become less reliant on trade. South Korean President Moon Jae-in announced a 16% hike in the minimum wage for the start of 2018, along with big increases in government spending, a bid to drive up wages and domestic consumption.

Many economists support the push for more spending in principle but worry about whether government is a sustainable answer.

In China, despite recovering exports, analysts worry about risks of a prolonged economic slowdown, mainly because of high debt levels, struggles with industrial overcapacity and likely unsustainable real-estate booms. Beijing kept bank lending taps open so that growth would remain strong heading into October's pivotal Communist Party Congress, but that event is now over.

In Singapore, the government has stepped up public spending even as it continues promoting industries such as financial services and tourism. Those industries have indeed grown, though not so much that Singapore can expect to see much faster overall growth, economists say.

"Once the cyclical recovery of trade slows down, it's going to be very difficult to grow if [Singapore] doesn't have domestic demand to generate this," said Ms. Nguyen of Natixis.

Write to Jon Emont at jonathan.emont@wsj.com

HONG KONG -- A synchronous upturn across major economies is reviving hopes that a multiyear lull in global trade is finally reversing and will lift emerging markets that built their economies around exports.

In Asia, the world's factory floor, exports are up sharply, including gains of 18.5% from a year ago in South Korea, 11% in Singapore and 20% in Vietnam. Chinese exports are up 5.5%, a rebound from the past two years, when exports contracted.