6) Assume that for the T = 2 time periods case, you have estimated a simple regression in changes model and found a statistically significant positive intercept. This implies a. a negative mean change in the LHS variable in the absence of a change in the RHS variable since you subtract the earlier period from the later period b. that the panel estimation approach is flawed since differencing the data eliminates the constant (intercept) in a regression c. a positive mean change in the LHS variable in the absence of a change in the RHS variable
d. that the RHS variable changed between the two subperiods