? Open wolf4.lpj
? This program runs bivariate probit models on the WTP for WMP and WDP

? create; lna = log(a)$
? create; lnb = log(x7)$

? namelist; demo = educ2,age,gender,child$
? namelist; nonuse = altruis2,bequest2,exist2,ethical2$
? namelist; info = know,read,seen$

? Test whether DK = NO (chi-square = 91.68 [9 df])
create; if(yes1new = 0) yes3 = 1$
create; if(yes1new = 1) yes3 = 0$
create; if(yes1new=-999) yes3 = 2$
logit; lhs=yes3 
;rhs = one,lna,plantrp2,income3,ely,nonuse
;rst = b1,b2,b3,b4,b5,b6,b7,b8,b9,b1,b2,b3,b4,b5,b6,b7,b8,b9
$

? Test whether DK = YES (chi-square = 60.31 [9 df])
create; if(yes1new = 0) yes4 = 0$
create; if(yes1new = 1) yes4 = 1$
create; if(yes1new=-999) yes4 = 2$
logit; lhs=yes4 
;rhs = one,lna,plantrp2,income3,ely,nonuse
;rst = b1,b2,b3,b4,b5,b6,b7,b8,b9,b1,b2,b3,b4,b5,b6,b7,b8,b9
$

? Determinants of DK
create; if(yes4 = 2)DK=1;(else)DK=0$
probit; lhs=dk
;rhs = one,income3,altruis,children$

? Bivariate Probit with selection; rho is equal to 1 and significant
create ;dk2=1-dk$
bivariate; lhs = yes1,dk2
;rh1 = one,lna,plantrp2,income3,ely,nonuse
;rh2 = one,income3,altruis2,child
;selection
$

? What to do ... estimate bivariate probits after dropping DKs

dstat; rhs = demo,nonuse,info$

? Dropping DKs with next line:
reject; yes1new=-999$

? Dropping DKs with next line:
reject; yes1new=-999$


bivariate ;lhs = yes1,yes2
;rhs = one,lna,ely
;rh2 = one,lnb,ely
$

wald 
;START = B; VAR = VARB 
;labels = b1,b2,b3,b4,b5,b6
;fn1 = exp(-(b1+b3)/b2)
;fn2 = exp(-(b4+b6)/b5)
;fn3 = exp(-(b1)/b2)
;fn4 = exp(-(b4)/b5)
;fn5 = fn1-fn2
;fn6 = fn3-fn4
;fn7 = fn3-fn1
;fn8 = fn4-fn2
$


bivariate ;lhs = yes1,yes2
;rhs = one,lna,plantrp2,income3,ely,nonuse
;rh2 = one,lnb,plantrp2,income3,ely,nonuse
$

? need to change these means ! 
wald 
;START = B; VAR = VARB 
;labels = b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,b17,b18
;fn1=b1
+b3*.40625000
+b4*39.886364
+b5*.48863636
+b6*.56250000
+b7*.64204545
+b8*.64204545
+b9*.78409091
;fn2=b10
+b12*.40625000
+b13*39.886364
+b14*.48863636
+b15*.56250000
+b16*.64204545
+b17*.64204545
+b18*.78409091
;fn3 = exp(-(fn1)/b2)
;fn4 = exp(-(fn2)/b11)
;fn5 = fn3-fn4
$

bivariate ;lhs = yes1,yes2
;rhs = one,lna,plantrp2,income3,ely,nonuse,info
;rh2 = one,lnb,plantrp2,income3,ely,nonuse,info
$

wald 
;START = B; VAR = VARB 
;labels = b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,b17,b18
;fn1=b1
 +b3*.36567164
 +b4*40.820896
 +b5*.51865672
 +b6*.50373134
 +b7*.59701493
 +b8*.60074627
 +b9*.75000000
;fn2=b10+
 +b12*.36567164
 +b13*40.820896
 +b14*.51865672
 +b15*.50373134
 +b16*.59701493
 +b17*.60074627
 +b18*.75000000
;fn3 = exp(-(fn1)/b2)
;fn4 = exp(-(fn2)/b11)
;fn5 = fn3-fn4
;fn6 = fn3*exp(((1/b2)*(1/b2))/2)
;fn7 = fn4*exp(((1/b11)*(1/b11))/2)
;fn8 = fn6-fn7
$


bivariate ;lhs = yes1,yes2
;rhs = one,lna,plantrp2,income3,ely,nonuse,demo
;rh2 = one,lnb,plantrp2,income3,ely,nonuse,demo
$

wald 
;START = B; VAR = VARB 
;labels = b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,b17,b18,
          b19,b20,b21,b22,b23,b24,b25,b26
;fn1=b1
 +b3*.36567164
 +b4*40.820896
 +b5*.51865672
 +b6*.50373134
 +b7*.59701493
 +b8*.60074627
 +b9*.75000000
+b10*14.948864
+b11*49.798295
+b12*.62784091
+b13*.53409091
;fn2=b14+
 +b16*.36567164
 +b17*40.820896
 +b18*.51865672
 +b19*.50373134
 +b20*.59701493
 +b21*.60074627
 +b22*.75000000
+b23*14.948864
+b24*49.798295
+b25*.62784091
+b26*.53409091
;fn3 = exp(-(fn1)/b2)
;fn4 = exp(-(fn2)/b15)
;fn5 = fn3-fn4
$



bivariate ;lhs = yes1,yes2
;rhs = one,lna,plantrp2,income3,ely,nonuse,demo,info
;rh2 = one,lnb,plantrp2,income3,ely,nonuse,demo,info
$

