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. Hello, I'm Helen Joyce, the finance editor of the Economist.

Welcome to Money Talks.

Coming up on the program.

What is the secret to a good trade agreement?

Trade creates disruptions in exactly the same way technological change does.

We do a lot of things to ensure that the losers from technological change we take care of.

We have safety blankets, we have retraining, we have social insurance, and we have rules about what kind of

technological changes, you know, is acceptable what kind isn't.

The rapid rise and fall of the And Bang Empire.

Now we're used to things going quickly in China, but even by Chinese standards

this was remarkably fast growth to go from basically nothing

to a company with more than $300 billion of assets in less than 15 years. First, a growing number of companies are cutting ties at the National Rifle Association

after the school's shooting in Florida. Airlines including United and Delta, car rental companies like Enterprise

and Hertz and insurance companies, are ending the discounts that they offer to

the NRA's 5 million members. Activists are encouraging people to boycott Apple, Amazon and Google's YouTube

because they carry NRA TV. However Warren Buffett, the chief executive of

Berkshire Hathaway, said that it would be ridiculous for the congomerous not to do business

with gunmakers. Krister Koskuller, our finance correspondent, joins us on the line from

New York. What will the business impact of this attempted boycott be, Krister?

It really depends on how the balance plays out. So the

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