In a second best environment, the optimal policy choice sometimes follows the first best rules. This note lays down the information structure and separability assumptions under which this property holds in a variety of setups. -- separability ; second best optimality ; indirect taxes ; Samuelson...

In a second best environment, the optimal policy choice sometimes follows the first best rules. This note lays down the information structure and separability assumptions under which this property holds in a variety of setups.