Stacey Vanek Smith

The gender pay gap exists for a variety of reasons. Discrimination is one; educational experience and job choice are others. The fields that employ a lot of women tend to pay less.

The superhero universe may be a fantasy (sorry, superfans), but that doesn't mean superheroes are free from the laws of economics. Quite the reverse, in fact: superheroes are subject to the dismal science, just like the rest of us. That's how Brian O'Roark sees it, anyhow.

More than 60 million years ago, the Tyrannosaurus rex roamed North America. Today, they're fetching 7 figures from museums and private buyers all over the world. There is a thriving market for dinosaur fossils and T-Rex is at the top of the food chain... but some people say this market is bad for science.

Today on The Indicator: the economics of dinosaur fossils. How does one come to own a T-Rex? Who buys them? And... aren't fossils priceless?

In the first few months of the year, the data we got about the economy was a little worrying. As a whole, it made some economists - and some of us - feel a little pessimistic about our economic future. The data pointed to fewer jobs being added to the economy, lackluster retail sales, and lower global growth projections from international agencies like the World Bank and the International Monetary Fund.

But lately, it seems like these indicators have been picking up, which seems to be a good sign for the economy. Today on The Indicator, is everything really awesome?

As cities all over the world grow, they're struggling with crowded streets and polluted air. New York City has decided to try out one possible solution: congestion pricing. Drivers will soon be charged a toll to enter certain crowded neighborhoods. Officials hope it will cut down on traffic and bring in badly needed funds to help repair the city's public transportation system.

Today on the show, Stacey Vanek Smith and Darius Rafieyan venture out into Midtown Manhattan during rush hour to see if congestion pricing is the solution that New York needs.

Today on the show, two indicators from our sibling podcast, The Indicator from Planet Money.

First, The Indicator goes to Georgia, to talk with a peanut farmer dealing with two major economic disasters: A hurricane and a trade war with China.

Then The Indicator turns to the World Happiness Report, and finds that the United States of America, despite its prosperity, only ranks 19th in overall happiness, which is kind of sad.

When Benjamin Franklin said the only two certainties in life are death and taxes, he wasn't talking about income taxes. America didn't really even have an income tax until 1913. Up until then, the U.S. relied on tariffs to raise revenue.

On today's Indicator, we explore the history of the income tax in the U.S. to find out how and why the government came up with the idea of taxing people's pay.

One of our self-described "introverted" listeners asked us: "Is my introverted-ness costing me money?"

We posed that question to Miriam Gensowski, an assistant professor of economics at the University of Copenhagen who studies the connection between personality traits and lifetime outcomes. She found that the answer is yes, introverts tend to earn less than extroverts over time — but there are some caveats.

Some of the research referenced in this story:

Q-W-E-R-T-Y, or "QWERTY," are the first six letters on most keyboards in English-speaking countries. That letter sequence seems random. And over time, some have tried to break our QWERTY spell with different letter sequences, but QWERTY has always prevailed — and the reasons contain some economic lessons.

To tell this story, we brought in economist Tim Harford, host of "Fifty Things That Made The Modern Economy" for the BBC World Service.

New York City is grappling with a measles outbreak. There have been 283 reports of measles in Brooklyn alone, compared to more than 500 nationwide, according to the Centers for Disease Control and Prevention. Mayor Bill de Blasio declared a public health emergency last week, requiring people living in parts of Brooklyn to get vaccinated.

Measles can cause serious long-term harm, to individuals and to the economy. On today's show, we examine how high the costs can go, and where they are incurred.

International trade may have made the world a more peaceful place, and the economies that partake in trade more efficient. But the gains that have come from international trade haven't been spread evenly around the world. Some workers do better than others, and some economies have benefited more than their counterparts. Which means there are many critics of international trade out there, some of whom serve in the highest levels of government. At one extreme, these trade skeptics say we should turn back the clock on trade.

Many economists and politicians argue that international trade has been a good thing. Countries that open themselves up for trade tend to be more peaceful, more efficient, and consumers can get cheaper and more varied goods. But it has also contributed to rising income inequality, as some workers lose out from the benefits of trade.

Today on The Indicator: how does trade affect inequality, and how did it get to be that way?

More than 70 percent of the world's maple syrup comes from the Canadian province of Quebec. Producing maple syrup is very dependent on the weather, but global demand doesn't quit just because of a bad spring. So the maple syrup producers of Quebec set production quotas to control over-production and a reserve, to make sure the supply never runs dry. That's right, there's a global strategic reserve of maple syrup.

Today on The Indicator, big maple. How Quebec's supply management system affects the rest of the syrup-producing world, and what that means for your breakfast table.

President Donald Trump just announced plans for a new round of U.S. tariffs on European products. The list includes aircraft materials, wine, cheese, motorcycles ... and even escargots. The new round appears to be retaliation for Europe's subsidies to planemaker Airbus. It's part of a spat that goes back nearly 15 years... and it's complicated. Because Europe has accused the U.S. of subsidizing its own planemaker, Boeing. Today on the show, a look at what's behind this latest round of proposed tariffs — and what this means for the economies of Europe and the U.S.