Encourage French people to declare their income online (rather than by mail) without using any financial incentives or obligations.
Nudges were designed using social norm and leveraging the default choice. These levers were activated in various communications : by SMS, email and in the explanatory note of the income declaration form.
The nudge led to 1.1 million increase in online declarations.
This intervention received multiple industry awards (Trophée d’Or du Marketing 2014, ESOMAR 2014 et 2015)