ThSQCA: An R Package for Threshold-Sweep Qualitative Comparative Analysis

Qualitative comparative analysis (QCA) requires thresholds to construct sets from continuous scales, but a standard analysis is fixed to a single set of thresholds and does not directly reveal how the sufficiency structure changes when the target level of the outcome or the judgment criterion for a condition changes. This article introduces the R package ThSQCA, which uses the QCA package as its computational engine and provides a common workflow to run, aggregate, visualize, and report analyses that systematically vary the outcome threshold, the condition thresholds, or both. Using simulated data constructed for methodological illustration, we show that raising the target level of the outcome narrows the result from multiple sufficient paths to a single path (with lower consistency and higher coverage) and eventually yields no solution. We also show that varying the judgment criterion for a condition can make a solution disappear or produce a solution supported by very few cases. ThSQCA does not select an appropriate threshold automatically; it is a diagnostic workflow that clarifies the range over which a conclusion holds and the points at which it changes.