model{
#N = nobs
for(i in 1:N){

# visit 1;
# marginal treatment assignment model, visit 1;
a_1s[i] ~ dbern(pa_1s[i])
pa_1s[i] <- ilogit(bs10)

# conditional treatment assignment model, visit 1;
a_1[i] ~ dbern(pa_1[i])
pa_1[i] <- ilogit(b10 + b11*w1[i] + b12*w2[i] + b13*L1_1[i] + b14*L2_1[i])

# visit 2;
# marginal treatment assignment model, visit 2;
a_2s[i] ~ dbern(pa_2s[i])
pa_2s[i] <- ilogit(bs20 + bs21*a_1s[i])

# conditional treatment assignment model, visit 2;
a_2[i] ~ dbern(pa_2[i])
pa_2[i] <- ilogit(b20 + b21*w1[i] + b22*w2[i] + b23*L1_1[i] + b24*L2_1[i] + b25*L1_2[i] + b26*L2_2[i] + b27*a_1[i])

# export quantity in full posterior specification;
w[i] <- (pa_1s[i]*pa_2s[i])/(pa_1[i]*pa_2[i])
}

#prior;
bs10~dnorm(0,.01)
b10~dnorm(0,.01)
b11~dnorm(0,.01)
b12~dnorm(0,.01)
b13~dnorm(0,.01)
b14~dnorm(0,.01)
bs20~dnorm(0,.01)
bs21~dnorm(0,.01)
b20~dnorm(0,.01)
b21~dnorm(0,.01)
b22~dnorm(0,.01)
b23~dnorm(0,.01)
b24~dnorm(0,.01)
b25~dnorm(0,.01)
b26~dnorm(0,.01)
b27~dnorm(0,.01)
}