After performing psmatch2, should you always: drop if _weight == . ? (these essentialy have not been used for matching) and was recommended by Oyvind Snilsberg
DATA USED:
webuse cattaneo2
//Does alcohol affect bweight
drop mmarried mhisp fhisp foreign deadkids nprenatal monthslb order mbsmoke mrace frace prenatal birthmonth lbweight fbaby prenatal1
**Creating macros
global treatment alcohol //intervention/treatment
global ylist bweight //outcome
global xlist mage medu msmoke //variables to match on t
As you can see THESE are the results after psmatch2:
//Calculate psscore using psmatch2
psmatch2 $treatment $xlist, outcome($ylist) neighbor(3) bw (0.06) common logit
the results were
| psmatch2:
psmatch2: | Common
Treatment | support
assignment | On suppor | Total
-----------+-----------+----------
Untreated | 4,492 | 4,492
Treated | 150 | 150
-----------+-----------+----------
Total | 4,642 | 4,642
After _weight is dropped when == . the total no of treated and untreated will change when performing:
tab medu _treated, column
+-------------------+
| Key |
|-------------------|
| frequency |
| column percentage |
+-------------------+
Mother's | 1 if alcohol consumed
education | during pregnancy
attainment | 0 1 | Total
-----------+----------------------+----------
0 | 5 4 | 9
| 1.49 2.67 | 1.85
-----------+----------------------+----------
1 | 2 0 | 2
| 0.60 0.00 | 0.41
-----------+----------------------+----------
2 | 1 0 | 1
| 0.30 0.00 | 0.21
-----------+----------------------+----------
5 | 1 0 | 1
| 0.30 0.00 | 0.21
-----------+----------------------+----------
6 | 1 0 | 1
| 0.30 0.00 | 0.21
-----------+----------------------+----------
8 | 4 1 | 5
| 1.19 0.67 | 1.03
-----------+----------------------+----------
9 | 10 5 | 15
| 2.98 3.33 | 3.09
-----------+----------------------+----------
10 | 47 19 | 66
| 13.99 12.67 | 13.58
-----------+----------------------+----------
11 | 28 14 | 42
| 8.33 9.33 | 8.64
-----------+----------------------+----------
12 | 140 62 | 202
| 41.67 41.33 | 41.56
-----------+----------------------+----------
13 | 20 9 | 29
| 5.95 6.00 | 5.97
-----------+----------------------+----------
14 | 17 5 | 22
| 5.06 3.33 | 4.53
-----------+----------------------+----------
15 | 10 3 | 13
| 2.98 2.00 | 2.67
-----------+----------------------+----------
16 | 40 20 | 60
| 11.90 13.33 | 12.35
-----------+----------------------+----------
17 | 10 8 | 18
| 2.98 5.33 | 3.70
-----------+----------------------+----------
Total | 336 150 | 486
| 100.00 100.00 | 100.00
.
As the analysis should be done with those that have a weight and have been used in the matched sample.
DATA USED:
webuse cattaneo2
//Does alcohol affect bweight
drop mmarried mhisp fhisp foreign deadkids nprenatal monthslb order mbsmoke mrace frace prenatal birthmonth lbweight fbaby prenatal1
**Creating macros
global treatment alcohol //intervention/treatment
global ylist bweight //outcome
global xlist mage medu msmoke //variables to match on t
As you can see THESE are the results after psmatch2:
//Calculate psscore using psmatch2
psmatch2 $treatment $xlist, outcome($ylist) neighbor(3) bw (0.06) common logit
the results were
| psmatch2:
psmatch2: | Common
Treatment | support
assignment | On suppor | Total
-----------+-----------+----------
Untreated | 4,492 | 4,492
Treated | 150 | 150
-----------+-----------+----------
Total | 4,642 | 4,642
After _weight is dropped when == . the total no of treated and untreated will change when performing:
tab medu _treated, column
+-------------------+
| Key |
|-------------------|
| frequency |
| column percentage |
+-------------------+
Mother's | 1 if alcohol consumed
education | during pregnancy
attainment | 0 1 | Total
-----------+----------------------+----------
0 | 5 4 | 9
| 1.49 2.67 | 1.85
-----------+----------------------+----------
1 | 2 0 | 2
| 0.60 0.00 | 0.41
-----------+----------------------+----------
2 | 1 0 | 1
| 0.30 0.00 | 0.21
-----------+----------------------+----------
5 | 1 0 | 1
| 0.30 0.00 | 0.21
-----------+----------------------+----------
6 | 1 0 | 1
| 0.30 0.00 | 0.21
-----------+----------------------+----------
8 | 4 1 | 5
| 1.19 0.67 | 1.03
-----------+----------------------+----------
9 | 10 5 | 15
| 2.98 3.33 | 3.09
-----------+----------------------+----------
10 | 47 19 | 66
| 13.99 12.67 | 13.58
-----------+----------------------+----------
11 | 28 14 | 42
| 8.33 9.33 | 8.64
-----------+----------------------+----------
12 | 140 62 | 202
| 41.67 41.33 | 41.56
-----------+----------------------+----------
13 | 20 9 | 29
| 5.95 6.00 | 5.97
-----------+----------------------+----------
14 | 17 5 | 22
| 5.06 3.33 | 4.53
-----------+----------------------+----------
15 | 10 3 | 13
| 2.98 2.00 | 2.67
-----------+----------------------+----------
16 | 40 20 | 60
| 11.90 13.33 | 12.35
-----------+----------------------+----------
17 | 10 8 | 18
| 2.98 5.33 | 3.70
-----------+----------------------+----------
Total | 336 150 | 486
| 100.00 100.00 | 100.00
.
As the analysis should be done with those that have a weight and have been used in the matched sample.
