Why do some big successful brands go bust?

Toast is back for a new series, taking a look at the decisions that often left investors burnt.

I'm Sean Farrington, a BBC business journalist. I'll be hearing about the hype.

They're going to do the deal that makes them the most money at that point of time.

And I'm picking what went wrong, talking to

owners and employees to ask, what can we learn? It was being undercut by similar rivals. It just

couldn't survive. Toast. Listen first on BBC Sounds. Hello and welcome to more or less on the

BBC World Service. I'm Ruth Alexander. The Nobel

Memorial Prize in Economic Sciences was awarded jointly this week to William Nordhaus and Paul

Roma. To find out more about their work, I spoke to one of their biggest fans. Tim Harford.

Remember me? Yeah, exactly. How are you? Yeah, I'm fine. Thank you very much. How are you?

I'm pleased to be on the other side of the microphone. I'm sure. I'll tell you all about two of my

favourite economists. William Nordhaus and Paul Romer were I think top of most people's lists to win it.

It still means this was a bit of a surprise because I think people hadn't made a connection

between their work. They didn't work together. I think it makes perfect sense, actually.

Aha. Why? They both study growth, and they both study really the invisible products and consequences

of growth. So Nordhaus studies climate change, and the way that climate change interacts with the economy

and the way that policies that we might implement to deal with climate change, how they might

affect the economy. So you can answer questions like, should we levy a carbon tax? Will that be

too economically damaging? How many jobs will it cost? Will it actually save the planet or not?

That's the focus

of Nordhaus's modelling. And he's been working on this since 1975. Romer focuses on what causes

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