New Delhi: Indian lawmakers who win closely fought elections often pay off their local political debts by engineering the award of village road-building jobs to contractors from their caste, a US-French study has found.

It has added that these roads have a higher probability of never being built.

The two major findings by Jacob N. Shapiro from Princeton University and Jonathan Lehne and Oliver Vanden Eynde from the Paris School of Economics are:

• After a close contest at an Assembly seat, the probability that contracts under the Pradhan Mantri Gram Sadak Yojana in that constituency will go to someone sharing the new MLA's surname rises from an average 4 per cent during the predecessor's term to 7 per cent during the incumbent's tenure.

(Since people sharing the surname are only a subset of the MLA's caste brethren, the actual proportions of same-caste contracts should be higher than the 4 and 7 per cent that the researchers recorded.)

• The possibility of the road never being completed rises by 86 per cent if the contractor has the same surname as the MLA.

(All decisions on Yojana projects are to be taken by the panchayat and block authorities, but obviously, the researchers imply, the MLAs do engage in some influence-peddling.)

The study, "Building connections: Political corruption and road construction in India", has been published in the Journal of Development Economics.

"The probability of an incomplete road is significantly higher when the road is built by a contractor who shares the MLA's last name than (when it's built) by other contractors in the same location," Shapiro said in an email response to queries from The Telegraph.

He said the researchers had compared data on the Yojana website, which often erroneously listed a project as completed, with the findings of the 2011 census to identify the "missing" roads (those that stayed unfinished).

Shapiro said the researchers studied 4,058 Assembly elections across 2,632 constituencies in 24 states since 2001, a year after the launch of the Yojana, which aims to provide all-weather roads to all villages by 2019.

They matched the surnames of the winner in each election with those of Yojana contractors active in their constituency before and after the election. Some 88,020 road agreements were signed in these constituencies during the sample period.

Shapiro said the researchers found that 497 roads were "missing" after presumably preferential allocation to contractors sharing the MLAs' surnames, affecting 857,000 villagers.

"The share of roads connected by (awarded to) such contractors is modest but the increase in the probability of missingness within that subset is quite large," he said.

"What we find is that across hundreds of close elections, there is a consistent increase in the number of contractors who share the last name of the MLA who wins the election. The chance that you would see these shifts by chance across so many close elections is exceedingly small."