Several lakh people from Bihar, Uttar Pradesh, Jharkhand and Odisha live and work in Punjab's industrial cities, in the knitwear units, the foundries, the steel rolling mills, the brick kilns and the fields.
They live in dense settlements with poor water, no sewerage and insecure tenure. Their children attend Punjab government schools, in Punjabi, which they learn.
They are not registered to vote in Punjab in most cases and have no political representation there, which is why their conditions have not improved with the state's income.
A second generation is growing up in Punjab, speaking Punjabi, with no land or connection in the state of origin and no standing in the state of residence.
Punjab has been an emigrant society for a century and has become a destination society without noticing, and it treats its own migrants roughly as its emigrants have been treated elsewhere.
Nothing has been written about them.
The workforce in Ludhiana's hosiery, Mandi Gobindgarh's furnaces and Jalandhar's leather units is largely from Bihar, Uttar Pradesh and eastern India, and has been for thirty years.
The pattern is seasonal for agriculture and permanent for industry, and the second group has children in Punjab schools and no count anywhere of how many.
Punjab's own labour left for abroad and was replaced by labour from further east. The state's politics has almost no vocabulary for the second half of that sentence.