New Delhi, March 22 -- By 4 May, voters in West Bengal, Kerala, Tamil Nadu, Assam and the union territory of Puducherry will have chosen new legislative assemblies. Polling runs from 9 April to 29 April.

On the face of it, Indian voters exercise their choice freely. But how do they arrive at that choice?

Political parties and their candidates mount intense, expensive campaigns, including tours, posters, social media blitzes and door-to-door outreach to persuade voters they are the best option. Promises of development and infrastructure are standard. Though rarely acknowledged openly, caste and religion continue to exert an outsized influence. Economic growth and jobs remain central themes.

Yet in recent elections, cash transfers have e...