natstrat - Obtain Unweighted Natural Strata that Balance Many Covariates
Natural strata can be used in observational studies to
balance the distributions of many covariates across any number
of treatment groups and any number of comparisons. These strata
have proportional amounts of units within each stratum across
the treatments, allowing for simple interpretation and
aggregation across strata. Within each stratum, the units are
chosen using randomized rounding of a linear program that
balances many covariates. For more details, see Brumberg et al.
(2022) <doi:10.1111/rssa.12848> and Brumberg et al.(2023)
<doi:10.1093/jrsssc/qlad010>. To solve the linear program, the
'Gurobi' commercial optimization software is recommended, but
not required. The 'gurobi' R package can be installed by
following the instructions at
<https://docs.gurobi.com/projects/optimizer/en/current/reference/r/setup.html>
after claiming your free academic license at
<https://www.gurobi.com/academia/academic-program-and-licenses/>.