dropUnanimous {pscl}

drop unanimous votes from rollcall objects and matrices

Description

Drop unanimous votes from rollcall objects and rollcall matrices.

Usage

dropUnanimous(obj, lop = 0)

Arguments

obj

object, either of class rollcall or matrix

lop

numeric, non-negative integer, less than number of legislators represented in obj. Roll calls with lop or fewer legislators voting in the minority are dropped. Default is 0, meaning that unanimous votes are dropped.

Details

Unanimous votes are the equivalent of test items that all subjects score “correct” (or all subjects scores “incorrect”); since there is no variation among the legislators/subjects, these votes/items provide no information as to latent traits (ideology, preferences, ability). A reasonably large number of rollcalls in any contemporary U.S. Congress are unanimous.

Specific methods are provided for objects of class rollcall or matrix.

Value

A rollcall object or a matrix depending on the class of object.

Author(s)

Simon Jackman [e-mail]

See Also

dropRollCall, rollcall, summary.rollcall, ideal

Examples

data(s109)
s109.working <- dropUnanimous(s109)
summary(s109.working)