Q2. What is the effect of the ex-ante optimal mechanism?
The authors also show that, if the cost of information acquisition is small, then, surprisingly, the ex-ante optimal mechanism is often ex-post inefficient.
Q3. What is the way to improve the optimal ex-post efficient mechanism?
It will be shown that if the cost of information acquisition is small enough, then the optimal ex-post efficient mechanism can be improved upon by replacing a continuation mechanism with an ex-post inefficient continuation mechanism.
Q4. What is the probability that the deviator is asked to report a signal?
Since the SP orders the voters independently of the realizations of the signals,p (A ∩B) = p (s) 2i+ d N ,where (2i+ d) /N is the probability that the deviator is asked to report a signal if a decision is made after a sequence with length 2i+d.
Q5. What is the argument that the first-best mechanism is not incentive compatible?
The authors argue that for given p and c, there always exists a k0 ∈ N such that the mechanism is not incentive compatible if the SP stops asking voters only if |d| ≥ k0.