verify_inputs_EMD

Check that the ratio, strata, and treated indicator provided to <code>generate_qs()</code>
are in the correct forms and that the desired ratio is feasible
across the population.

internal

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/>.

Katherine Brumberg

natstrat

Obtain Unweighted Natural Strata that Balance Many Covariates

verify_inputs_EMD function

<dl><dt>ratio</dt>
<dd>a numeric or vector specifying the desired ratio of controls to `treated` in
each stratum. If there is one control group and all treated units should be included,
this can be a numeric. Otherwise, this should be
a vector with one entry per treatment group, in the same order as the levels of
<code>z</code>, including the treated level. If <code>NULL</code>, <code>q_s</code> should be specified.</dd>
<dt>st</dt>
<dd>a stratum vector with the <code>i</code>th entry equal to the
stratum of unit <code>i</code>. This should have the same order of units and length
as <code>z</code>.</dd>
<dt>z</dt>
<dd>a factor with the <code>i</code>th entry equal to the treatment of unit <code>i</code>.</dd>
<dt>treated</dt>
<dd>which treatment value should be considered the treated units. This
must be one of the values of <code>z</code>.</dd></dl>

Arguments

Verify the inputs to the earthmover's distance problem — verify_inputs_EMD

<dl>

<dt>ratio</dt>
<dd>a numeric or vector specifying the desired ratio of controls to `treated` in
each stratum. If there is one control group and all treated units should be included,
this can be a numeric. Otherwise, this should be
a vector with one entry per treatment group, in the same order as the levels of
<code>z</code>, including the treated level. If <code>NULL</code>, <code>q_s</code> should be specified.</dd>


<dt>st</dt>
<dd>a stratum vector with the <code>i</code>th entry equal to the
stratum of unit <code>i</code>. This should have the same order of units and length
as <code>z</code>.</dd>


<dt>z</dt>
<dd>a factor with the <code>i</code>th entry equal to the treatment of unit <code>i</code>.</dd>


<dt>treated</dt>
<dd>which treatment value should be considered the treated units. This
must be one of the values of <code>z</code>.</dd>

</dl>

verify_inputs_EMD: Verify the inputs to the earthmover's distance problem

Description

Usage

Value

Arguments