Consider the regression model with the heterogeneous coefficient. Y = Boi + BX + vi where (v. X. Poi, B) are i.i.d random variables with Bo = E (Boi) and B = It is possible to show E (Bu) that the model can be written as Y; = Bo+BX; +u, where u; = (Boi - Bo) + And, it is also possible to show that E[u[X]=0 when we assume that E (Boi|X) = Bo, E (B|X) = B, and E (vi|X) = 0. (you don't need to prove these results here.) Based on these results, we can conclude that under the current setting, regression of Y on X and an intercept will yield a consistent estimation of the ( ). Fill the parenthesis with three words.