optimize_asymmetric_treatment_assignment

Given a total budget and asymmetric treatment and control costs, calculate the
number of treatments and controls that optimize the variance of the estimator. 
The number of treatments is rounded up by default.

Computes experimental designs for a
two-arm experiment with covariates via a number of methods:
(0) complete randomization and randomization with forced-balance,
(1) Greedily optimizing a
balance objective function via pairwise switching. This optimization
provides lower variance for the treatment effect estimator (and higher
power) while preserving a design that is close to complete randomization.
We return all iterations of the designs for use in a permutation test,
(2) The second is via numerical optimization
(via 'gurobi' which must be installed, see <https://www.gurobi.com/documentation/9.1/quickstart_windows/r_ins_the_r_package.html>)
a la Bertsimas and Kallus,
(3) rerandomization,
(4) Karp's method for one covariate,
(5) exhaustive enumeration to find the
optimal solution (only for small sample sizes),
(6) Binary pair matching using the 'nbpMatching' library,
(7) Binary pair matching plus design number (1) to further optimize balance,
(8) Binary pair matching plus design number (3) to further optimize balance,
(9) Hadamard designs,
(10) Simultaneous Multiple Kernels.
In (1-9) we allow for three objective functions:
Mahalanobis distance,
Sum of absolute differences standardized and
Kernel distances via the 'kernlab' library. This package is the result of a stream of research that can be found in
Krieger, A, Azriel, D and Kapelner, A "Nearly Random Designs with Greatly Improved Balance" (2016) <arXiv:1612.02315>,
Krieger, A, Azriel, D and Kapelner, A "Better Experimental Design by Hybridizing Binary Matching with Imbalance
Optimization" (2021) <arXiv:2012.03330>.

Adam Kapelner

GreedyExperimentalDesign

Greedy Experimental Design Construction

David Azriel

Abba Krieger

optimize_asymmetric_treatment_assignment function

<dl><dt>c_treatment</dt>
<dd>The cost of a treatment assignment. Default is <code>NULL</code> for symmetric costs.</dd>
<dt>c_control</dt>
<dd>The cost of a control assignment. Default is <code>NULL</code> for symmetric costs.</dd>
<dt>c_total_max</dt>
<dd>The total cost constraint of any allocation. Either this or <code>n</code> must be specified. Default is <code>NULL</code>.</dd>
<dt>n</dt>
<dd>The total cost constraint as specified by the total number of subjects. Either this or <code>c_total</code> must be 
specified. Default is <code>NULL</code>.</dd></dl>

Arguments

Author

Compute Optimal Number of Treatments/Controls — optimize_asymmetric_treatment_assignment

<dl>

<dt>c_treatment</dt>
<dd>The cost of a treatment assignment. Default is <code>NULL</code> for symmetric costs.</dd>


<dt>c_control</dt>
<dd>The cost of a control assignment. Default is <code>NULL</code> for symmetric costs.</dd>


<dt>c_total_max</dt>
<dd>The total cost constraint of any allocation. Either this or <code>n</code> must be specified. Default is <code>NULL</code>.</dd>


<dt>n</dt>
<dd>The total cost constraint as specified by the total number of subjects. Either this or <code>c_total</code> must be 
specified. Default is <code>NULL</code>.</dd>

</dl>

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optimize_asymmetric_treatment_assignment: Compute Optimal Number of Treatments/Controls

Description

Usage

Value

Arguments

Author

Examples