DEAS 2.0

deas is the current Stata package for Data Envelopment Analysis and related
commands. The main command remains dea.

The recommended public package is deas version 2.0.29 (15 August 2026).
This package update adds tfdea 2.1.0; the main dea command remains at
version 2.0.28. The main command is:

help dea

The current public dea.ado header is:

*! version 2.0.28  05aug2026
*! Requires: Stata 16.0 or later

Included Commands

• dea
• dea_bootstrap
• dea_congestion
• dea_crosseff
• dea_crossgame
• dea_fuzzy
• dea_malmquist
• dea_nash
• dea_network
• dea_sbmundesirable
• dea_stackelberg
• dea_sw2007
• dea_window
• convnls
• stoned

Internal helper files are included as _dea_ipm.ado, _dea_simplex.ado,
and _dea_spbland.ado.

convnls implements convex nonparametric least squares (StoNED stage 1),
and stoned implements the StoNED error decomposition and efficiency
estimation stage. The accompanying forthcoming paper and online appendix are
distributed as convnls_stoned_forthcoming.pdf and
online_appendix_forthcoming.pdf.

Legacy Files

Older local versions of dea.ado are preserved under
legacy/dea_ado_versions/. See MANIFEST.md for source paths, versions,
and checksums.

Stata Net Install

When these files are served from a Stata-readable web directory, users can
install with:

net from <sourceforge-url>
net install deas, all replace

Use which dea after installation to verify which copy Stata resolves. The
older dea.pkg is retained only for historical compatibility and is not
advertised in stata.toc; do not install both package names. Existing users
should install deas, all replace so that one coherent set of ado and help
files is selected.

License, attribution, and article status

The software is distributed under AFL-3.0 and is provided on an "AS IS" basis
without warranties, subject to the terms in LICENSE_CODE.txt. Users are
responsible for independently validating their data, specifications,
computations, and results.

Author-prepared Stata Journal accepted-manuscript materials, when present, are
not part of the software license. They are provided without charge for
non-commercial use and without permission to create derivative works. They are
not the final published StataCorp/SAGE PDF. See ARTICLE_FILE_STATUS.md and
ARTICLE_REUSE_NOTICE.md.