Attention at all passengers. You can now book your train tickets on Uber and get 10% back in Uber credits to spend on your next train journey.

So no excuses not to visit your in-laws this Christmas.

Trains now on Uber. T's and C's apply check the Uber app. You're listening to Money Talks from Economist Radio, our weekly podcast on economics, finance and the world of business.

I'm Samia Keynes, trade and globalization editor at The Economist.

And coming up today, a forgotten heroine of economics.

Now in June of 1921, I received the degree of Doctor of Philosophy in Economics.

It was a great occasion because I was the first black woman in the United States to qualify and to receive a degree.

So said, Sadie Tana, Marcel Alexander, the first African American to get a PhD in economics.

A hundred years ago, on the day that she got it from the University of Pennsylvania,

there was quite a celebration.

And I can well remember marching down Broad Street from Mercantile Hall to the Academy of Music

when there were photographers from all over the world taking my picture.

Today, most over the world taking my picture. Today most economists don't know much about

Alexander which is partly because of what happened next. All of the glory of that

occasion faded however quickly when I tried to get a position.

Sadie Alexander couldn't get a job in academic economics.

In fact, it would be years until black women got their

first teaching positions in American universities. Her daughter described

there being no way for her to make a living in the profession.

Alexander eventually got a job at a life insurance company, but ultimately decided to retrain,

and she went on to have a pretty stunning career as a lawyer.

She fought for civil rights, she pushed for the desegregation of Philadelphia's hotels,

...