Annex 6.3 A Summary of Experimental Methods

The methods used to select the counterfactual or control group, known as evaluation designs, can be broadly classified into three categories experimental, quasi-experimental, and nonexperimental. These three evaluation designs vary in terms of feasibility, cost, degree of clarity, validity of results, and extent of selection bias. This annex, adapted from Ravallion (2008), summarizes these designs. 

Many methods are available for selecting a counterfactual group using matching techniques, some more robust, some less robust. The following three methods are likely to produce a robust counterfactual  

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