1. www.worldbank.org/hdchiefeconomist The World Bank Human Development Network Spanish Impact Evaluation Fund

2. Christel Vermeersch The World Bank IMPACT EVALUATION Introduction to Parallel Tracks METHODS

3. This morning: Parallel Sessions Covering: methods for evaluating impact (the how) The content of the policy and technical tracks is the same It’s just the approach that is different o Policy track: intuition o Technical track: intuition + econometrics

4. What session should you attend? If you have studied… multivariable regression in a statistics and/or econometrics course. If your role is… 1. Design of impact evaluation methodologies. 2. Data analysis. …Then please consider attending the technical sessions.

5. What session should you attend? If you have NOT studied… multivariable regression in a statistics and/or econometrics course. If your role is… 1. Using evaluation results to inform policy making. 2. Management and oversight of evaluations. 3. Contracting of consultants to implement evaluations. …Then please consider attending the policy sessions. Or if in doubt…

6. Quiz: Technical question 1 In the following equation: y is… α 0 is… x 2 is… ε is… y=α 0 + β 1 x 1 + β 2 x 2 + + ε

7. Quiz: Technical question 2 In the following two expressions, b is… b=(X’X) -1 X’y 1. A naive estimator 2. The OLS estimator 3. The XLS estimator 4. The impact estimator for large samples 5. Don’t know 1. A naive estimator 2. The OLS estimator 3. The XLS estimator 4. The impact estimator for large samples 5. Don’t know b=b= ∑(x i - x) (y i - y) ∑(x i - x) 2 ¯¯ ¯

8. Quiz: Technical question 3 The sum of 3 independent normally distributed variables has what kind of distribution? 1. A student-t distribution 2. A normal distribution 3. A Poisson distribution 4. A strange distribution 5. Don’t know 1. A student-t distribution 2. A normal distribution 3. A Poisson distribution 4. A strange distribution 5. Don’t know

9. Quiz: Technical question 4 Under the Gauss conditions, the least squares estimator is: 1. BLUE 2. YELLOW 3. RED 4. None of the above 5. Don’t know 1. BLUE 2. YELLOW 3. RED 4. None of the above 5. Don’t know

10. Quiz: Results Got all 4 questions correct? please consider attending the technical sessions. Otherwise, please consider attending the policy sessions.

11. Thank You

12. ? Q & A ?