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title: "copulaSQM" output: github_document

copulaSQM

Copula-Based Stochastic Frontier Quantile Model

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Description

copulaSQM implements a copula-based stochastic frontier quantile model using the asymmetric Laplace distribution (ALD) and simulated likelihood estimation.

The model extends classical stochastic frontier analysis (SFA) by:

• Estimating conditional quantile frontiers
• Allowing asymmetric error distributions
• Modeling dependence between noise and inefficiency via copulas

This framework is suitable for applied production analysis, efficiency measurement, and heterogeneous performance evaluation.

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Model

The production model is:

[ Y_i = X_i \beta + V_i - U_i ]

where:

• ( V_i ) follows an asymmetric Laplace distribution
• ( U_i \ge 0 ) is a one-sided inefficiency term
• Dependence between ( V_i ) and ( U_i ) is modeled using copulas available in VineCopula

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Installation

# install.packages("devtools")
# devtools::install_github("woraphonyamaka/copulaSQM")
install.packages("copulaSQM", repos = c('https://woraphonyamaka.r-universe.dev', 'https://cloud.r-project.org'))

library(copulaSQM)