Function to find pair matches using a distance matrix. Called by opt.nearfar to discover optimal near-far matches.

Description

Given values of percent sinks and cutpoint, this function will find the corresponding near-far match

Usage

1
matches(X, imp.var = NA, tol.var = NA, sinks = 0, IV = NA, cutpoint = NA)

Arguments

X

A matrix of measured confounders (with column names) on which to make “near” in the matching

imp.var

A list of (up to 5) named variables to prioritize in the “near” matching

tol.var

A list of (up to 5) tolerances attached to the prioritized variables where 0 is highest penalty for mismatch

sinks

Percentage of the data to match to sinks (and thus remove) if desired; default is 0

IV

Vector of instrumental variable values on which to make “far” in the matching

cutpoint

Value below which individuals are too similar on IV; increase to make individuals more “far” in match

Details

Default settings yield a "near" match on only observed confounders in X; add IV, sinks, and cutpoint to get near-far match.

Value

A two-column matrix of row indices of paired matches

Author(s)

Joseph Rigdon jrigdon@stanford.edu

References

Lu B, Greevy R, Xu X, Beck C (2011). Optimal nonbipartite matching and its statistical applications. The American Statistician, 65(1), 21-30.

See Also

opt.nearfar