Empirical Techniques: Explain how each of the following techniques reduce the possibility of omitted variables when analyzing the impact of education policy.

1. Using random assignment (RCT) to evaluate the impact of a college scholarship on college attendance.
2. Using family/sibling fixed effects to determine the effects of attending college on future earnings.
3. Using a regression discontinuity to determine the effect of a prestigious college scholarship on future earnings. Scholarship eligibility is determined by an SAT score cutoff.