Misbah Rana is, of course, the 12-year-old formerly known as Molly Campbell. She sparked a huge furore in September by running away from her Scottish mother's custody in the Hebrides to her Pakistani father's home in Lahore. Seeing footage of her a few days after her flight, I realised that, apart from Jemima Khan, it was the first time I'd seen a press image of a British-born person in Pakistan smiling. But despite Misbah's protests that she had travelled to Pakistan willingly, suspicions persisted in Britain that she couldn't actually be happy, that she must have been taken them under duress, possibly for a forced marriage.

"The question 'Why would anyone raised in Britain want to live in Pakistan?' was implicit in the tone of the reporting," says Pakistani novelist Kamila Shamsie, who lives between Karachi, London and New York State. And she's right. Perhaps this shouldn't be surprising - the British High Commission in Islamabad does, after all, receive 100 reports of forced marriage each year. And even second-generation Pakistanis, returning to Pakistan willingly for arranged marriages, attest to culture shock, at the very least. Home from Home, a collection of personal accounts from British Pakistanis now living in Mirpur - the remote rural district where most Pakistani migrants to Britain originate - includes a litany of unwelcome surprises, from outdoor loos and lizard-dodging to terminal boredom.

But the Ranas don't have culture shock and Lahore is no Mirpur: it's a large metropolitan centre. And Misbah isn't the only one who prefers it. Watching her story unfold reminded me of all the British-born women I've met on recent trips to Lahore who have happily chosen to relocate. The country is attracting a new generation of socially mobile British Pakistani women or BBCDs (British Born Confused Desis), as bitchier Pakistanis call us. As Pnina Werbner, a social anthropologist, explains, "There are an enormous number of young British Pakistani girls now who, unlike their parents, went to university, and a whole new world is opening up to them. They have to decide what to do and make a lot of choices. [Their experience can be] a cultural no-man's land and one way out for them is to return home."

But that only goes a short way to explaining exactly what makes these women swap life in a first-world democracy for one in a developing nation ruled by a military dictatorship their parents struggled to leave. Pakistan is a society where gang rape is used as a form of tribal punishment, hundreds of pregnant women are in jail for adultery and husbands routinely forbid their wives to work.

Natasha Anwar, a 35-year-old doctor who moved to Pakistan five years ago, says one of the key attractions for her was the freedom from racial tension. Born to Pakistani parents in Chingford, north-east London, Anwar says she "never felt part of British society, whereas now I feel like I'm home. I don't feel edgy and anxious any more." She certainly looks comfortable in the grounds of the hospital and research centre in Lahore where she works as a research scientist - excellent career prospects are apparently another bonus.

For Anwar, her primary school years in Britain were great, but at Chingford High School the racist bullying began. "We used to get snowballed at the bus stop and the usual 'Paki go home' taunts. One day my brother and I were walking home with my neighbour, who was also Pakistani, and this boy ran past us, threw chilli powder in my neighbour's face and hair, and then smashed the glass jar at our feet. We didn't even tell our parents, because, well, that's what you do as a minority. When my mum talks about her childhood [in Pakistan], she oozes this feel good factor. I wanted to tap into that feeling for my children, too."

Before she left Britain, a young Muslim man on the tube "with his socks pulled up over his shalwar" upbraided her for not dressing modestly enough. "I was being pulled in two different directions, one completely westernised and one fundamentalist. It was so tense. As Asians, we're continuously fighting for our rights, fighting for equality, fighting for this, fighting for that. We're wasting so much energy, so much time, so much of what's in us on fighting, and what's left? This whole loss of identity is something a lot of British Asians have to struggle with and I don't want my children to have it, when they could be getting on with what is more important in life."

So, after finishing her doctorate, Anwar moved to Lahore in summer 2001, and met her husband at a party. Their children are growing up in the same house as their grandparents, surrounded by extended family (whose support Anwar cites as a bonus), and her younger sister has since followed her to Lahore, leaving only her parents and a brother in Chingford.

Another attraction for British-born women moving to Pakistan is, of course, financial. Standing in the Ranas' vast lounge - about twice the size of my north London flat - I'm reminded of just how far sterling can stretch over here. As Shamsie puts it, "If you're at the top of the pile, you can be very comfortable."

Not only that, but the most affluent sections of society can prove much more liberal than might be expected. Sadia Rasheed, 27, a British-born Pakistani from Hounslow, relocated in 1998 when she married her Pakistani husband, an architect. At first she found her elite new social world so disturbingly libertarian she almost fled back to Britain. In the rarefied circles she moves in she has "become more broad-minded than I was in London," she says. "For instance, the way young women dress [at parties] here is more revealing and I just had to get over it." She laughs at me when I ask if she has met any gay people in Pakistan. "Of course, no one cares," she says.

Rasheed values a work/life balance that has enabled her to establish her interior design business while her daughter was a toddler. She admits that this balance comes from being able to employ servants, though. "There are only advantages here for the upper classes, there's nothing you can't do with the right contacts. But it's very tough for everyone else. It is difficult to survive as a single woman in this society, but some do do it - the strong ones."

Miranda Husain, a 35-year-old journalist from Essex, is one of them. After travelling the world and losing both her parents in her 20s, she decided to move to her father's country of origin in 2003 to be near her remaining family. Like Misbah, her father was Pakistani and her mother was white British. There are many things that she loves about Pakistan - seeing people praying casually on the roadside, for instance - but after three years of pushing social boundaries as a single woman, she's not sure if Lahore can be a permanent home. She misses the breathing space of a multicultural society. "To be accepted here you have to surrender your own identity. It's not just about adapting, it's about losing [your British] culture and I don't agree with that at all." As she drives us from a city-centre restaurant at midnight, unaccompanied, we attract creepy leers at every traffic light. It makes me wonder how she has stayed so sane.

Ironically, given her sister Misbah's situation, Tahmina is preparing to head back to married life in Blackburn. But what about Misbah and the family being together? "Oh, that's not a problem," the sisters tell me, pointing to the webcam on their computer. Tahmina sees herself firmly as a British Muslim or British Pakistani, but she is keenly aware of her father's experiences. "Even now, after four years in Pakistan, when we go to the park, he still does this joke: 'What's that, can you hear that? I can't hear it. I can't hear anyone calling me a Paki, can you? See anyone throwing stones? No?' If I have a daughter, I'd like to bring her here for a while so she doesn't become too confused, so she knows who she is."