Hey there, happy Friday. I don’t know about you, but my tax refund wasn’t all that big or beautiful this year, but we’ll do the numbers in today’s newsletter. We’ll also explain all the different kinds of crude oil and why more American drilling can’t replace the stuff that was stuck in the Strait of Hormuz. Plus, some market forces that could shift your summer travel plans and we unpack the weirdest story on Wall Street this week. But first: Where in the world is Kai Ryssdal? — Tony Wagner, newsletter editor

The population of the United States and other wealthy nations is getting older. That means the global economy is relying more and more on developing countries, many of which have younger populations and, thus, younger workers.

One example is Vietnam. “We're seeing a country at its peak,” said ADP Chief Economist Nela Richardson, “Marketplace’s” partner on this series. “This is a country where there are two working-age adults for every dependent, either over 65 or under 15.” That workforce has attracted a lot of attention from American companies looking for workers. And that demand, in turn, is creating opportunities for Vietnam.

“In every other advanced, wealthy country, that ‘golden spot’ led to wealth creation, economic growth, and it led to technological advancement,” said Richardson. “However, it’s not going to last forever. We have about 10 years before that sweet spot, that ‘golden age,’ turns into another aging population.”

Binh Tay Market, located in Ho Chi Minh City’s Chinatown, is frequented by both wholesale customers and regular people. When Ryssdal and Richardson visited on a weekday morning, it was buzzing with activity: people on motorbikes delivering goods and shoppers perusing the stalls.

Married couple Dũng Anh Nguyễn and Vân Thanh Mai have been running one such stall for 38 years. They sell bolts of fabric and, more recently, have started selling scarves in order to cater to tourists. As they’ve gotten older, they’ve considered what might happen to their business. According to Mai, their children are unlikely to take it over.

“They are white-collar workers. They have office jobs,” said Mai. “A day at the market, it's not stable like an office job.”

About seven miles away from Binh Tay Market, on the outskirts of Ho Chi Minh City, workers in a sewing factory put together dresses that end up in U.S. retailers like Target and Anthropologie.

“Right now, around 90% of our total product, we export,” said Henry Pham, CEO of Dony Garment and the owner of the factory. “And 10% is local.”

Pham employs around 300 people. He said one of his priorities is to invest back into those workers and make their lives a little easier by, for example, installing air conditioning in his factory. But sudden changes in U.S. tariff policy have thwarted his plans, leaving his factory only partially air-conditioned.

“I’m most worried about policy change,” said Pham. “We have to prepare around a minimum of two months for one [clothing] order. And you see that right now, the policy can change after two weeks.”

At a refinery, crude oil ultimately gets converted into three main products: gasoline, diesel and jet fuel. But there’s a wide spectrum of crude out there ranging in fluidity (light or heavy) and sulfur content (sweet or sour).

“There are as many types of crude oil as there are Cabernet Sauvignons from California,” said Tom Kloza, an independent oil analyst.

The type of oil that you get will dictate how complex the conversion process is. The lighter and sweeter it is, the simpler it is to turn it into transportation fuel, experts told Marketplace.

There are three major oil benchmarks that serve as a reference point for traders: West Texas Intermediate, which represents a light, sweet crude oil extracted from Texas, North Dakota and Louisiana. Brent, another light, sweet crude oil that’s extracted from the North Sea near Europe. Then there’s Dubai crude, which is a medium, sour oil.

Here’s what you need to know about the different types of oil out there, starting with sweet vs. sour.

The crash that killed two pilots at LaGuardia Airport last month came as the country's airspace is under pressure.

There’s a shortage of air traffic controllers, and federal efforts to build up that workforce will take years to see results. Meanwhile, passenger numbers continue to grow, and traffic is expected to increase especially fast at large hubs, according to the FAA.Those  31 airports, like Atlanta, Chicago O’Hare, and LAX, each handle at least 1% of the country’s commercial passengers each year.

But the U.S. also has hundreds of smaller airports, which could play a bigger role in alleviating congestion at the largest hubs, if regulators and airlines choose to use them.

One small hub positioning itself to handle more traffic is Patrick Leahy Burlington International Airport in Burlington, Vermont. In late March, the airport unveiled a terminal upgrade, funded largely by a $34 million Congressional earmark.

The terminal’s layout and its four new jet bridges can accommodate larger aircraft, and the waiting areas are significantly more spacious than the narrow hallway where four of the airport’s gates used to be clustered.

Passenger Donna Druchunus of Barton, Vermont, knows that hallway well.

“I used to wait in that long hallway, and it was so hot,” she said. “It never felt clean, because it was just so old and worn out.”

Still, Druchunus said she usually chooses to fly out of Burlington, even though she has other options. Boston Logan, a major international hub that handles more than a thousand flights a day, is about a three hour drive from her home. Burlington’s airport, with about 30 departures a day, is just under two hours away, and despite that hallway, “it is a nicer airport and it's quieter and there's no wait times,” Druchunus said.

With Burlington’s terminal upgrade to replace the cramped waiting area, her choice is even easier.

“It's, like, amazing,” Druchunus said as she waited for the first flight to leave from one of the new terminal’s gates.

 “There's a fireplace and a kid's playroom and everything. I had no idea that it was going to be like that.”

This track has nearly 230 million streams on Spotify, but it’s gone hyper-ultra-diamond on social media and television, as one of the most “synced” songs of 2025.

“Syncs” are the background music you see in TikTok, or hear in commercials, it’s music designed to blend in so seamlessly with video you hardly notice it. Much of this library music is bespoke, created for video editing software of massive libraries licensed out to businesses — you might even hear some on Marketplace. Sometimes they’re pop hit soundalikes, but increasingly pop hits like “Midnight Sun” are starting to sound like syncs themselves, Ryan Bradley reported recently for the New York Times (gift link).

This all might sound a bit grim, the natural conclusion of an art form that’s been devalued and commodified by decades of industry shifts. But syncs are also a lifeline for working musicians, who can carve out a middle-class living cranking out these tracks in semi-anonymous studios. It’s not much but it’s honest work — we can’t all be Zara Larsson. Bradley came on “Marketplace” last week to talk more about it.