CSDE Affiliate Leigh Anderson (Director of EPAR, Public Policy) and the Evans Policy Analysis and Research Group (EPAR) have launched a new series on “Choices with Consequences.”  The series of blogs and technical briefs illustrate the implications of alternative cleaning and variable construction decisions when constructing agricultural indicators, though applicable to other topics using household survey data. You can read the first brief on treating outliers, which also features a visualization tool to understand the implications of different identifying, trimming and replacing choices.  Key takeaways from this first “outlier” brief are:

• Outliers, extremely high or low values of a continuous variable are common in survey data. They can be atypical but valid observations or the result of data collection or processing errors.
• Appropriately handling outliers can reduce their distortion of summary statistics or analytical results, and transparency around methods can support reproducibility.
• The outcome of an outlier treatment method depends on the type of measurement error that generated outlier observations, the overall sample size, the subgroups of interest, and the degree of variation across those subgroups.
• We developed a simple tool to explore the consequences of different methods, using household survey data from the LSMS-ISA

The entire brief and tool can be found at: https://epar.evans.uw.edu/category/methods/choices-with-consequences/