London School of Economics
NBER Working Papers and Publications
|February 2015||The Catch-22 of External Validity in the Context of Constraints to Firm Growth|
with Dean Karlan: w20971
We document the presence of multiple and varied constraints to small and medium firm growth. This presents both a practical problem for business training programs and a challenge to academic economists trying to identify mechanisms though which these programs may affect outcomes. External validity needs theory. This pushes researchers to narrowly defined and highly selected sample frames, which limits the potential for clear, generalizable policy prescriptions. Ultimately, larger samples, multi-arm evaluations, process documentation, and narrowly-focused, theory-supported empirical work are all needed, but the complexity of the problem limits what we learn from any single study.
Published: Greg Fischer & Dean Karlan, 2015. "The Catch-22 of External Validity in the Context of Constraints to Firm Growth," American Economic Review, vol 105(5), pages 295-299. citation courtesy of
|May 2014||To Charge or Not to Charge: Evidence from a Health Products Experiment in Uganda|
with Dean Karlan, Margaret McConnell, Pia Raffler: w20170
In a field experiment in Uganda, a free distribution of three health products lowers subsequent demand relative to a sale distribution. This contrasts with work on insecticide-treated bed nets, highlighting the importance of product characteristics in determining pricing policy. We put forward a model to illustrate the potential tension between two of these important factors, learning and anchoring, and then test this model with three products selected specifically for their variation in the scope for learning. We find the rank order of percentage change of shifts in demand matches theoretical predictions, although the differences are not statistically significant, and only two of three pairwise comparisons match when the reductions are specified in percent terms. These results highlight t...