/* This file creates 3 variables for each ppn:
* zeros82 = 1 if va, K, ph or ph2 are <=0 in 1982
* zeros87                                 in 1987
* zeros92                                 in 1992
*
* zeros282 = 1 if obs4 or obs480 <10      in 1982
* zeros287
* zeros292
*
* This file will be merged with st828792; 
*
* Tto obtain a
* balanced panel, simply delete any obs for which
* zeros82=1 or zeros87=1 or zeros92=1
*****************************************************/
options compress=no;
libname in 'D:/cm/';
libname un 'D:/enrico/new/data';
libname on 'D:/enrico/imported/data';


data tmp82; set in.st828792;
if yr ^=82 then delete;
K = bae+mae;
ph2 = (ph/pw)*(te-pw);
zeros82  =0;
zeros282 =0;
if va  <=0                  then zeros82=1;
if ph  <=0                  then zeros82=1;
if ph2 <=0 or ph2 =.        then zeros82=1;
if K   <=0 or K=.           then zeros82=1;
if medu4 =. or medu6 =.     then zeros82=1;
if medu480 =. or medu680 =. then zeros82=1;
if obs4<10 or obs480 <10    then zeros282 =1;
keep ppn zeros82 zeros282;
proc sort; by ppn;

data tmp87; set in.st828792;
if yr ^=87 then delete;
zeros87  =0;
zeros287 =0;
K = bae+mae;
ph2 = (ph/pw)*(te-pw);
if va  <=0                  then zeros87=1;
if ph  <=0                  then zeros87=1;
if ph2 <=0 or ph2 =.        then zeros87=1;
if K   <=0 or K=.           then zeros87=1;
if medu4 =. or medu6 =.     then zeros87=1;
if medu480 =. or medu680 =. then zeros87=1;
if obs4<10 or obs480 <10    then zeros287 =1;
keep ppn zeros87 zeros287;
proc sort; by ppn;

data tmp92; set in.st828792;
if yr ^=92 then delete;
K = bae+mae;
ph2 = (ph/pw)*(te-pw);
zeros92  =0;
zeros292 =0;
if va  <=0                  then zeros92=1;
if ph  <=0                  then zeros92=1;
if ph2 <=0 or ph2 =.        then zeros92=1;
if K   <=0 or K=.           then zeros92=1;
if medu4 =. or medu6 =.     then zeros92=1;
if medu480 =. or medu680 =. then zeros92=1;
if obs4<10 or obs480 <10    then zeros292 =1;
keep ppn zeros92 zeros292;
proc sort; by ppn;

data in.errors2; merge tmp82 tmp87 tmp92; by ppn;
proc means;