anominate {anominate} | R Documentation |
alpha-NOMINATE: Ideal Point Estimator
Description
anominate
is the function that takes a rollcall
object and fits the Bayesian (MCMC-based) alpha-NOMINATE model described in Carroll et al. (2013). The method estimates the structure of political actors' utility functions from roll call data with the inclusion of a separate parameter denoted as alpha. alpha values of 1 indicate normal (Gaussian) utility, while alpha values of 0 indicate quadratic utility.
Usage
anominate(rcObject, dims=1, nsamp=1000, thin=1, burnin=500, minvotes=20,
lop=0.025, polarity=1, random.starts=TRUE, verbose=FALSE, constrain=FALSE)
Arguments
rcObject |
An object of class |
dims |
integer, number of dimensions to estimate. Must be nonnegative and cannot exceed 10 dimensions. |
nsamp |
interger, total number of iterations for the sampler. |
thin |
integer, thinning interval for the MCMC samples. |
burnin |
integer, number of iterations to be discarded. |
minvotes |
integer, minimum number of votes required for a legislator to be included in the analysis. |
lop |
A proportion between 0 and 1, the cut-off used for excluding lopsided
votes, expressed as the proportion of non-missing votes on the minority side.
The default, |
polarity |
a vector specifying the legislator in the data set who is conservative on
each dimension. For example, |
random.starts |
logical, indicating whether initial values for the legislator and bill parameters should be randomly drawn from a uniform distribution. If |
verbose |
logical, indicates whether the progress of W-NOMINATE and alpha-NOMINATE (at each 100th iteration of the MCMC sampler) should be printed to the screen. |
constrain |
logical, indicates whether alpha should be constrained to equal 1 rather than estimated. This option should be used if more than one dimension is being estimated, which makes the method equivalent to a Bayesian implementation of Poole and Rosenthal's (1997) NOMINATE model. |
Value
An object of class anominate
, which in this documentation is also referred to
as an alpha-NOMINATE object.
alpha |
An object of class |
beta |
An object of class |
legislators |
A object of class |
yea.locations |
A object of class |
nay.locations |
A object of class |
wnom.result |
An object of class |
Author(s)
Royce Carroll rcarroll@rice.edu
Christopher Hare cdhare@ucdavis.edu
Jeffrey B. Lewis jblewis@ucla.edu
James Lo lo@uni-mannheim.de
Keith T. Poole ktpoole@uga.edu
Howard Rosenthal hl31@nyu.edu
References
Royce Carroll, Jeffrey B. Lewis, James Lo, Keith T. Poole and Howard Rosenthal. 2013. “The Structure of Utility in Spatial Models of Voting.”' American Journal of Political Science 57(4): 1008-1028.
Jeffrey B. Lewis. https://voteview.com/
Keith Poole and Howard Rosenthal. 1997. Congress: A Political-Economic History of Roll Call Voting. New York: Oxford University Press.
See Also
'summary.anominate','plot.anominate','densplot.anominate','traceplot.anominate','simulateData', 'sen111', 'sen111_anom', 'rollcall'.
Examples
data(sen111)
sen111_anom <- anominate(sen111, dims=1, polarity=2,
nsamp=200, thin=1, burnin=100, random.starts=FALSE,
verbose=FALSE, constrain=FALSE)
# 'sen111_anom' can be retrieved quickly with:
data(sen111_anom)
# Summary statistics:
summary(sen111_anom)
# Graphical summaries:
plot(sen111_anom)
densplot.anominate(sen111_anom)
traceplot.anominate(sen111_anom)