Punjab has been sending people abroad for a hundred and twenty years and the reasons have changed three times.
The first wave, from about 1900, was labour: to the Canadian and American west coast, to the Kenya and Uganda railways, to Hong Kong, Shanghai, Malaya and Fiji, mostly men, mostly from the Doaba, mostly intending to return. It produced the Ghadar Party.
The second, after 1947 and especially from the 1950s, was to Britain: to the foundries and mills of the west midlands and Yorkshire, to Southall, to Birmingham, on labour vouchers, again heavily from the Doaba and heavily Ramgarhia and Jat.
The third, from about the 1990s and accelerating sharply since 2015, is students. Punjab sends more student visa applicants to Canada than any other Indian state. The IELTS coaching centre is now a fixture of every district town. Families sell or mortgage land to pay the fees.
The word dunki, from the Punjabi for donkey, describes the irregular overland route: Latin America, the Darien Gap, the southern United States border. People die on it every year.
Villages in the Doaba have houses locked and maintained by caretakers, gurdwaras funded from Vancouver, and schools with falling rolls. Emigration is the largest single fact about rural Punjab today and it is the least measured.
The pattern is a century and a quarter old: the west coast of North America before 1914, Britain from the 1950s, the Gulf from the 1970s, and Canada, Australia and Italy since.
What is different now is the age and the route. The study visa takes people at eighteen and nineteen, on a loan secured against land, and the intention on both sides is work rather than study.
A Doaba village with a closed house on every second plot and nobody under forty in it is the ordinary condition, and no policy anywhere addresses why it is happening.