(a) Describe the Head Start program. State: who it serves, and what it provides. (b) One way to estimate the effect of Head Start is to compare outcomes between participants and non-participants. What is one problem with doing that? Explain why. (c) Another way to estimate the effect of Head Start is to compare outcomes between siblings. List one benefit of this approach over the one in (b), and explain. List one problem with this approach, and explain. State whether this problem will lead us to over- or under-estimate the treatment effect of Head Start, and explain why. (d) In this question, I want you to only discuss the results for whites. One outcome used in this study was the picture Peabody vocabulary test score. What were the findings for this outcome when using the strategy described in (b)? You need to list the magnitude and interpret the magnitude. (e) What were the findings for this outcome in (d) when using the strategy described in (c)? You need to list the magnitude and interpret the magnitude. (f) Is the difference between your findings you discussed in (d) and (e) consistent with the problem you listed in (b)? Explain.