Multivariate Quantile-on-Quantile Regression R package mqqr version 1.0.0 Implements Multivariate Quantile-on-Quantile Regression (m-QQR) of Sinha, Ghosh, Hussain, Nguyen and Das (2023) <doi:10.1016/j.eneco.2023.107021>, extending the bivariate Quantile-on-Quantile regression of Sim and Zhou (2015) <doi:10.1016/j.jbankfin.2015.01.013> to include exogenous moderators and controls with optional interaction terms. For each pair of quantile levels (theta of the response and tau of the regressor) the package fits a locally-weighted quantile regression of y on the principal regressor x, a lagged dependent variable, moderators Z and the x*Z interaction terms, using Gaussian kernel weights on the empirical cumulative distribution function (CDF) distance. Bootstrap standard errors and Koenker-Machado pseudo R-squared are reported. Visualisations include 'MATLAB'-style 'Parula' and 'Jet' 3D surfaces, heatmaps and contour plots through 'plotly'. Software Depends: R (>= 3.5.0) Imports: quantreg (>= 5.0), plotly (>= 4.0.0), stats, utils, grDevices Suggests: knitr, rmarkdown, testthat (>= 3.0.0) Merwan Roudane <merwanroudane920@gmail.com> Comprehensive R Archive Network (CRAN) Merwan Roudane [aut, cre, cph], Avik Sinha [ctb] (Original m-QQR methodology), Nicholas Sim [ctb] (Original QQ regression methodology), Hongtao Zhou [ctb] (Original QQ regression methodology) GPL-3 2026-06-01 application/tgz https://CRAN.R-project.org/package=mqqr doi:10.32614/CRAN.package.mqqr