Party systems and roll-call utilities

PartySystemIndices: Rae fractionalization, Laakso-Taagepera and Golosov effective numbers. PartyDivergence: differences of party means and medians, overlap, and Rice cohesion. RollcallMatrix: legislator x vote matrix with Voteview codes. RollcallSummary: yeas, nays, minority shares, margins, participation. RollcallFilter: wnominate-style lopsided-vote and participation filtering (indices returned 1-based).

Usage

PartySystemIndices(shares)

PartyDivergence(positions, party, left, right, votes = NULL)

RollcallMatrix(legislator, vote, choice, yea = 1:3, nay = 4:6)

RollcallSummary(matrix)

RollcallFilter(matrix, lop = 0.025, minvotes = 20)

Arguments

shares

Vote or seat shares.

positions

Ideal points.

party

Party labels.

left, right

Labels of the two parties.

votes

Legislators x roll calls matrix (1 yea, 0 nay, NA).

legislator, vote, choice

Long-format records.

yea, nay

Codes counted as yea and nay.

matrix

Roll-call matrix.

lop

Minimum minority share.

minvotes

Minimum votes per legislator.

Value

List.

References

Golosov, G. V. (2010). The effective number of parties: a new approach. Party Politics 16, 171-192.

Poole, K., Lewis, J., Lo, J. and Carroll, R. (2011). Scaling roll call votes with wnominate in R. Journal of Statistical Software 42(14).

Examples

PartySystemIndices(c(50, 30, 20))$golosov
#> [1] 2.139979
RollcallMatrix(c("a", "a", "b", "b"), c(1, 2, 1, 2), c(1, 6, 4, 9))$matrix
#>      [,1] [,2]
#> [1,]    1    0
#> [2,]    0   NA