Remittances into Punjab run into billions of dollars a year. They are the largest single external income the state receives and there is no reliable district-level figure for them.
What they build is visible. Houses far larger than the family living in them, often locked. Gurdwara extensions in marble. Village gates. Sports grounds. Ambulances. Water coolers with a donor's name on them.
What they do not build is productive capacity. Very little remittance money goes into enterprise in Punjab, because the returns are poor and the sender is not there to run it. It goes into land, which pushes land prices to levels no farmer can justify from farming, and into construction.
Marriage markets have reorganised around it. A visa is an asset and is priced as one, and the resulting arrangements, including marriages entered into for immigration and abandoned afterward, have produced a category of abandoned wives large enough for the state to have set up specific legal machinery for it.
Emigration solves the individual problem and deepens the structural one. That is not a criticism of anyone who leaves.
The money builds houses, funds weddings, pays for the next person's ticket, buys land, and endows the gurdwara. It does not, in general, start businesses.
That is the criticism made of it and the answer is that a returning household buys the thing that is safe, and in Punjab that has always been land and standing.
It also sets the price of land. Agricultural land in the Doaba is priced against what a family abroad will pay, which is far above what farming it can return.