NES                   package:cmm                   R Documentation

_P_o_l_i_t_i_c_a_l _O_r_i_e_n_t_a_t_i_o_n _i_n _t_h_e _U_S, _t_h_r_e_e-_w_a_v_e _p_a_n_e_l _s_t_u_d_y

_D_e_s_c_r_i_p_t_i_o_n:

     Data from the US National Election Studies. Three-wave panel study
     measuring political orientation on a seven-point scale. The data
     are tabulated in Bergsma, Croon, and Hagenaars (2009, 4.4).

     Sections 4.2.1 and 4.3 in Bergsma, Croon and Hagenaars (2009).

_U_s_a_g_e:

     data(NES)

_F_o_r_m_a_t:

     A data frame with 408 observations on the following variables.

     '_T_1' Political orientation at time 1 (ordered): 1 = Extremely
          liberal 2 = Liberal 3 = Slightly liberal" 4 = Moderate 5 =
          Slightly conservative 6 = Conservative 7 = Extremely
          conservative

     '_T_2' Political orientation at time 2 (ordered): see 'T1'

     '_T_3' Political orientation at time 3 (ordered): see 'T1'

_S_o_u_r_c_e:

     US National Election Studies.

_R_e_f_e_r_e_n_c_e_s:

     Bergsma, W. P., Croon, M. A., & Hagenaars, J. A. P.
     (2009)._Marginal models for dependent, clustered, and longitudinal
     categorical data._New York: Springer.

     Examples in book: <URL:
     http://stats.lse.ac.uk/bergsma/cmm/R%20files/NES.R>

_E_x_a_m_p_l_e_s:

     data(NES)

     ####################################################################################
     # Models for marginal homogeneity over time (Section 4.2.1)

     # Marginal homogeneity : no change in political orientation over time

     at <- MarginalMatrix(c("T1", "T2", "T3"), list(c("T1"), c("T2"), c("T3")), c(7,7,7));
     bt1 <- ConstraintMatrix(c("T", "P"), list(c("T"), c("P")), c(3, 7));

     model1 <- list(bt1, "identity", at);

     start <- c(t(ftable(NES))) + .001;
     pihat <- MarginalModelFit(NES, model1,
         MaxSteps = 3000, StartingPoint = start,
         ShowProgress = 250, MaxError = 1e-28,
         CoefficientDimensions = c(3,7), ShowCoefficients = TRUE,
         ShowParameters = FALSE, Labels = c("T", "P"));

