There is an outfit that publishes the World Happiness Report. The primary measure is the "Cantril Life Ladder" (from Hadley Cantril, Patterns of Human Concern, 1965).
As far as I can tell, some 1000-odd people of age 15+ in each of 156 to 158 countries are asked by Gallup polling each year the following question, which in English reads:
As far as I can tell, some 1000-odd people of age 15+ in each of 156 to 158 countries are asked by Gallup polling each year the following question, which in English reads:
“Please imagine a ladder, with steps numbered from 0 at the bottom to 10 at the top. The top of the ladder represents the best possible life for you and the bottom of the ladder represents the worst possible life for you. On which step of the ladder would you say you personally feel you stand at this time?”The average for the country is supposed to reflect its level of happiness. The Cantril Life Ladder is available for India from 2006 onwards. The report also includes measures that one might think affects the answers given on the Cantril Life Ladder, such as per capita income and life expectancy, and survey measures such as perceived freedom to make life choices, perceived corruption, and so on. India is generally improving on these measures over the 2006-2018 time period. One interesting thing is that countries with poorer improvement on these measures can be happier than India.