Why do Americans work so much more than Europeans? Because America has lower marginal tax, says Prescott, the 2004 Economics Nobel Laureate.
The important observation is that the low labor supplies in Germany, France, and Italy are due to high tax rates. If someone in these countries works more and produces 100 additional euros of output, that individual gets to consume only 40 euros of additional consumption and pays directly or indirectly 60 euros in taxes.
I wonder where India stands.