Provides method used to check whether data have outlier in efficiency measurement
of big samples with data envelopment analysis (DEA). In this jackstrap method, the package
provides two criteria to define outliers: heaviside and k-s test. The technique was developed
by Sousa and Stosic (2005) "Technical Efficiency of the Brazilian Municipalities: Correcting
Nonparametric Frontier Measurements for Outliers."