The DID model can be described as:Y¡ =a +βDi+yt¡+ δ(D¡.tj)+ε, where D¡ means intervention,t¡ means time.Which parameter in the formula represents the true treatment effect

问答题Assuming that ρ represents the intraclass correlation within the group, ρ = 1 me

问答题Given the form: . In the form indicates potential outcome and indicates the treatment state. Which part indicates the selection bias? ()