•   •   •

I LEAVE A MESSAGE with the Mosaic people, who turn out to be a company called Experian. Their press officer, Bruno, calls me back. Over the phone he eulogizes Mosaic. He says it is incredibly accurate and used by everyone, more than fifty thousand businesses, including many credit-card companies.

I tell him I still don’t quite understand what it does.

“I’ll give you a demonstration,” Bruno replies. “Give me a postcode.”

“Ah,” I say. I scrabble frantically around my notes until I find Richard Cullen’s postcode—the postcode shared by the twenty or so households on the Cullens’ street.

“Uh . . . BA14 . . .” I begin, making it sound like I’ve just invented a postcode at random.

I hear him type it into his computer.

The Cullens, it turns out, belong to Mosaic’s Group B 11: “Happy Families: Families Making Good.” These are “older people on middle incomes . . . not highfliers up career ladders of large conglomerates.” Neighborhoods like this are “hardly centers of intellectual or aesthetic style.” Happy Families are “likely to be interested in adverts for financial products.”

“This is a culture,” concludes Mosaic, “that is keen to take advantage of easy credit.”

I later discover that a fledgling incarnation of Mosaic called ACORN (A Classification of Residential Neighbourhoods), which is also used by some credit-card companies, says of Richard Cullen’s postcode: “The interest in current affairs is low. They are educated to a low degree.” (ACORN was invented by the creator of Mosaic—Professor Richard Webber—but it is owned and operated by a company called CACI, and not by Experian.)

Then Bruno types my postcode into Mosaic.

“Wow!” he says. “You’re a Global Connector. Roman Abramovich is a Global Connector too.”

Bruno is clearly impressed.

“We bought before the boom,” I explain, slightly embarrassed.

“Not many Guardian journalists are Global Connectors,” says Bruno.

“My street isn’t that nice,” I say.

“Well, if we’ve got it wrong, you’re the exception that proves the rule,” says Bruno, a little defensively.

He reads out my profile. Nowhere does it say that we Global Connectors are likely to take advantage of easy credit, nor will we be interested in adverts for financial products.

The reason neither I nor my horrendous alter ego Titch don’t get nearly as much credit-card junk mail as Richard Cullen did is that our postcode, N1, suggests affluence. If I lived in a downmarket postal area, one more befitting Titch’s characteristics, he wouldn’t have been filtered out by Mosaic. He’d have been deluged.

Bruno invites me to Experian’s London offices. I’ve never heard of them. It turns out that they’re not only the power behind Mosaic, they are also Britain’s biggest credit-reference agency, with files on forty million people in Britain. Bruno gives me directions. I should walk down Park Lane, he says, turn onto Curzon Street, and after 150 yards I’ll see Leconfield House.

“Apparently it used to be MI5 headquarters,” says Bruno, “which is very appropriate, I suppose.”

“You’ve taken over MI5’s old building?” I repeat.

He laughs. “Yes,” he says.

•   •   •

LECONFIELD HOUSE was indeed MI5 HQ—between 1945 and 1976. And you can tell. It has no street number. Leconfield House is not number anything, Curzon Street. Inside, Experian’s offices are all beige and pine, like an airport hotel. Bruno arrives with another man—Professor Richard Webber, “the father of geodemographics.” This is the man who invented both Mosaic and ACORN.

It isn’t my imagination. As we walk to Conference Room A, Professor Webber is looking me up and down, categorizing me on the spot.

“You’re wearing training shoes,” he says, slightly baffled, because they don’t quite fit with the rest of my clothes.

“I walked here,” I explain. “I need comfortable shoes for walking.”

“Hm,” says Professor Webber.

•   •   •

PROFESSOR WEBBER’S WORK—profiling and categorizing the lifestyles of the nation—began in the 1970s when he was commissioned by Liverpool City Council to design a computer program that might explain certain nuances of geographical deprivation. Why were some poor areas prone to rioting when others weren’t? It turned out that some Liverpool ghettos had preponderances of “ethnics, drug issues, single parents, low levels of education,” whereas others had “high fertility, high church attendance,” and so on. Beefeater gin was shown to be particularly popular in certain areas.

“Until then,” Professor Webber says, “nobody knew the connection between neighborhoods and consumption. It wasn’t long before the private sector saw the potential.”

Ever since, the professor has been tallying and perfecting, buying up databases from the DVLA (Driver and Vehicle Licensing Agency), the electoral roll, the British Crime Survey, and so on, and augmenting this data with Experian’s own lifestyle surveys.

“Which Mosaic category do you fall into?” I ask the professor.

“Cultural Leadership,” he says.

“Are you a typical Cultural Leader?” I ask him.

“Yes,” he says.

Cultural Leadership: “These [highly fastidious] people are assured, secure and very discriminating. They spend their abundant wealth very carefully. They value the privacy of their homes and home life.

It doesn’t sound like any credit-card companies will be bombarding Professor Webber’s home with junk. Mosaic’s lifestyle data (Professor Webber writes the text himself) is often really quite impolite. For instance, when people within the category known as “Welfare Borderlines” purchase cosmetics, they are “likely to be striking accessories rather than means for displaying natural beauty.” The professor has, however, been most glowing about his own people, the Cultural Leaders.

•   •   •

I TELL BRUNO and Professor Webber about Richard Cullen’s suicide. I suggest that families like the Cullens are bombarded with junk because the direct-marketing departments of the lenders are guided by Mosaic pointers such as: “likely to be interested in adverts for financial products . . . keen to take advantage of easy credit,” and ACORN pointers like “educated to a low degree.” In the mathematical world of the credit industry’s computer lifestyle calculations, it strikes me that a consensus had been formed about the Cullens. The family needed the money, but because they owned their own home, there was something to seize if need be. And they weren’t smart enough to read the small print and spot the trap they were being beckoned into.

For a moment Bruno seems unsure how to respond to this. My impression is that he doesn’t want to downplay Mosaic’s significance, but neither does he want to admit that his company’s computer program played a role—however peripheral—in a suicide. So he shrugs and says, yes, some credit-card companies use Mosaic, but they use their own files too.

Before I met Professor Webber, I fancifully imagined him as a Caractacus Potts, a madcap inventor filled with sorrow at how the private sector had hijacked his brilliant machine. But when I ask him if he’s alarmed by any of Mosaic’s current uses, he says the opposite is true. He wishes the public sector were efficient enough to use Mosaic more.

“Our country,” he says, “would be better organized if they did.”

But this is beginning to change, says Bruno. For example, TV Licensing are using Mosaic to choose which areas to target with their vans.

•   •   •

MY LASTING MEMORY of my afternoon at Experian is Professor Webber and I, a Cultural Leader and a Global Connector, sitting inside these mysterious former MI5 headquarters in the heart of Mayfair, imperiously scrutinizing, via a computer slideshow, Welfare Borderlines.

As we looked at the slides I asked Professor Webber if he considered himself an academic, but he laughed scornfully and said he was a taxonomist. He said, “I like putting things into categories. Taxonomy is less authoritarian than academia.”