8. In Example 11.8 apply the serial odds ratio model of Fitzmaurice and Lipsitz (1995). A possible partial code is

where omega is a positive parameter.

model for (i in 1:N) z[i,s,t] < zli, s, t]~ { for (s in 1:T-1) { for (t in s+1:T) { equals (yli, s], 1) *equals (y [i,t], 1) +2*equals (y [i, s], 1) *equals (y [i, t], 0) +3*equals (y [i, s], 0) *equals (y [i, t], 1) +4*equals (yli, s], 0) *equals (y [i, t], 0) dcat (p[i, s, t, 1:4]) for (j in 1:4) (p[i,s,t,j]