The need for quasi-experimental methodology to evaluate pricing effects.

Family planning program managers may be easily misled by conclusions about the effects of price increases on the demand for services when the findings are based on pre-experiments such as the single-group pretest-posttest study, generally believed to be practical. This report presents financial and service data from clinics of the Asociación Pro-Bienestar de la Familia Ecuatoriana (APROFE) in Ecuador, which, analyzed according to the single-group pretest-posttest design, would suggest that the demand for intrauterine device services is inelastic. However, considerable demand elasticity is detected when data are analyzed according to more rigorous quasi-experimental designs. Using the single-group pretest-posttest design for pricing studies is too flawed to be considered practical. Wherever possible, strong designs should be used in operations research, especially in pricing studies.