You say you wanted to write a "big, fat London novel". Why?
There's that sense of global themes pressing on London. I don't think I wanted it to be representative, because you can shade into sounding like you're appointing UN delegates, but I did think about what the ground rules would be to have a thing that felt like it had a lot of London in it. I thought about it a lot at the start and then let the novel take over. I have a horror of going down dead ends, which you can easily do with a novel, spending months on it and then realising that it's all wrong. It's demoralising, because you don't get the time back.
How do you know when you've hit a dead end?
It's tricky, that, because you have mood swings anyway, writing a book. It's creeping realisation turning into dawning horror. As with anything else - a bit like a relationship - you can just tell. I spend an awful lot of time mulling it over at the start to try to get the architecture and the fundamentals in place, partly because I know I'm going to have those mood swings and because I have this horror of dead ends. So I spent a lot of time thinking about the building blocks.
Had you mapped the novel completely before starting to write?
Yes. The mapping out is a fun stage, because everything's reversible. A lot of things about the characters are predetermined and yet I'm still surprised by the things they say and do, page by page. It's that old argument: E M Forster talked about his characters escaping and Nabokov said, "Well, Forster's novels are so boring, you can't blame them for wanting to escape."
After all the planning, are you ever disappointed by the execution?
This is the first time I've ever felt I wrote the book I intended to. And the reason for that is I had this gap in which I went off and wrote Whoops! [his 2010 book about the financial crisis] and then came back and there was an enormous psychic distance. There were things I'd forgotten. I don't think that means it's automatically a better book but I did have that feeling that I was seeing it with a cold eye and, in a sense, the intentions with which I'd written it were no longer my intentions.
Sitting down to look at it at the end of 2010 and the start of 2011, I was non-metaphorically a different person from the person who had started thinking about that book at the end of 2005.
Your characters range from a Polish builder to a traffic warden. Did you want to give visibility to Londoners often ignored?
I was keen to have a novel that felt like London. I wouldn't state my aim in any terms more theorised and thought-through than that. I also wanted the book to have a democratic quality, in that attention is given to the characters equally and there's no sense that one person is inherently more important or more worthy of attention than another.
The title has an obvious double meaning and financial transactions link many of the characters. Is money our strongest bond?
Once you learn to "speak" money - which is what I felt I did through the research that led me to write Whoops! - you start to see it at work all around you. It's like a language, a code written on the surface of things; it's in flow all around us, all the time. You start to see the world in terms of the currents of money and capital running through it. I was keen to bring that view of things to bear in the novel and to see some of the specific ways in which specific sums of money exert different forces on different characters at different times.
You depict London as a fractured society. Have we lost all sense of community?
I think "community" in the sense in which politicians use it is largely a cant term. A lot of the time in modern Britain, certainly in urban life, we barely have any contact at all with the people around us. Add to that the divisive impact of the economic downturn and we are heading towards being a society in which the words "We're all in this together" are precisely the opposite of the truth. My hunch is that dividedness and fragmentation - which, as you imply, were on my mind when I wrote Capital - are likely to be increasingly pressing as themes: not just the 1 per cent and the rest but the tension between different generations and perhaps also between London and the rest of the country.
John Lanchester's "Capital" is published by Faber & Faber (£17.99)