I am interested in analyzing union membership for people who transition between employment and nonemployment in the CPS ORG.
I have noticed that there appear to be many people who appear in month 4 but not month 8 or month 8 but not month 4 of the survey.
I did a quick count of how many times each cpsidp appears in months 4 or 8. The data I am using are from January 2010 to December 2019, but this could be easily looked at in a smaller sample.
keep if inlist(mish,4,8) & eligorg == 1
duplicates tag cpsidp, generate(dups)
count_obs | Freq. Percent Cum.
------------+-----------------------------------
1 | 618,893 39.75 39.75
2 | 937,906 60.25 100.00
------------+-----------------------------------
Total | 1,556,799 100.00
From this, it looks like about 40 percent of the sample is in month 4 or month 8 (or neither) but not both. I know that people who left the survey in 2010 or people who first entered the survey in 2019 will not be included twice.
When I look at the date of these individuals only surveyed once, I see the following:
date | Freq. Percent Cum.
------------+-----------------------------------
2010m1 | 7,899 1.58 1.58
2010m2 | 8,225 1.64 3.22
2010m3 | 8,018 1.60 4.82
2010m4 | 8,486 1.69 6.51
2010m5 | 7,996 1.60 8.10
2010m6 | 8,450 1.69 9.79
2010m7 | 8,221 1.64 11.43
2010m8 | 8,246 1.64 13.07
2010m9 | 8,272 1.65 14.72
2010m10 | 8,337 1.66 16.39
2010m11 | 7,984 1.59 17.98
2010m12 | 8,301 1.66 19.64
2011m1 | 2,829 0.56 20.20
2011m2 | 2,862 0.57 20.77
2011m3 | 2,875 0.57 21.34
2011m4 | 2,868 0.57 21.92
2011m5 | 2,798 0.56 22.47
2011m6 | 2,884 0.58 23.05
2011m7 | 2,752 0.55 23.60
2011m8 | 2,830 0.56 24.16
2011m9 | 2,780 0.55 24.72
2011m10 | 2,968 0.59 25.31
2011m11 | 2,927 0.58 25.89
2011m12 | 2,963 0.59 26.48
2012m1 | 2,778 0.55 27.04
2012m2 | 2,844 0.57 27.61
2012m3 | 2,888 0.58 28.18
2012m4 | 2,895 0.58 28.76
2012m5 | 2,776 0.55 29.31
2012m6 | 2,850 0.57 29.88
2012m7 | 2,971 0.59 30.47
2012m8 | 2,875 0.57 31.05
2012m9 | 2,977 0.59 31.64
2012m10 | 2,951 0.59 32.23
2012m11 | 3,003 0.60 32.83
2012m12 | 3,026 0.60 33.43
2013m1 | 2,868 0.57 34.01
2013m2 | 2,961 0.59 34.60
2013m3 | 2,892 0.58 35.17
2013m4 | 2,970 0.59 35.77
2013m5 | 2,940 0.59 36.35
2013m6 | 2,884 0.58 36.93
2013m7 | 3,004 0.60 37.53
2013m8 | 2,961 0.59 38.12
2013m9 | 2,876 0.57 38.69
2013m10 | 3,043 0.61 39.30
2013m11 | 3,739 0.75 40.04
2013m12 | 3,651 0.73 40.77
2014m1 | 3,426 0.68 41.46
2014m2 | 3,762 0.75 42.21
2014m3 | 3,932 0.78 42.99
2014m4 | 3,762 0.75 43.74
2014m5 | 3,606 0.72 44.46
2014m6 | 3,790 0.76 45.22
2014m7 | 4,000 0.80 46.01
2014m8 | 3,942 0.79 46.80
2014m9 | 3,783 0.75 47.55
2014m10 | 4,059 0.81 48.36
2014m11 | 4,179 0.83 49.20
2014m12 | 4,215 0.84 50.04
2015m1 | 4,095 0.82 50.86
2015m2 | 4,069 0.81 51.67
2015m3 | 3,975 0.79 52.46
2015m4 | 4,201 0.84 53.30
2015m5 | 4,061 0.81 54.11
2015m6 | 4,119 0.82 54.93
2015m7 | 3,792 0.76 55.69
2015m8 | 3,834 0.76 56.45
2015m9 | 3,580 0.71 57.17
2015m10 | 3,950 0.79 57.95
2015m11 | 3,071 0.61 58.57
2015m12 | 3,182 0.63 59.20
2016m1 | 3,284 0.66 59.86
2016m2 | 3,218 0.64 60.50
2016m3 | 3,146 0.63 61.12
2016m4 | 3,242 0.65 61.77
2016m5 | 3,285 0.66 62.43
2016m6 | 3,335 0.67 63.09
2016m7 | 3,382 0.67 63.77
2016m8 | 3,461 0.69 64.46
2016m9 | 3,404 0.68 65.14
2016m10 | 3,288 0.66 65.79
2016m11 | 3,388 0.68 66.47
2016m12 | 3,401 0.68 67.15
2017m1 | 3,223 0.64 67.79
2017m2 | 3,251 0.65 68.44
2017m3 | 3,418 0.68 69.12
2017m4 | 3,132 0.62 69.74
2017m5 | 3,152 0.63 70.37
2017m6 | 3,075 0.61 70.99
2017m7 | 3,261 0.65 71.64
2017m8 | 2,940 0.59 72.22
2017m9 | 3,206 0.64 72.86
2017m10 | 3,070 0.61 73.48
2017m11 | 3,260 0.65 74.13
2017m12 | 3,123 0.62 74.75
2018m1 | 3,163 0.63 75.38
2018m2 | 3,090 0.62 76.00
2018m3 | 3,181 0.63 76.63
2018m4 | 3,113 0.62 77.25
2018m5 | 3,177 0.63 77.89
2018m6 | 3,178 0.63 78.52
2018m7 | 3,204 0.64 79.16
2018m8 | 3,018 0.60 79.76
2018m9 | 3,195 0.64 80.40
2018m10 | 3,051 0.61 81.01
2018m11 | 3,165 0.63 81.64
2018m12 | 3,092 0.62 82.25
2019m1 | 7,634 1.52 83.78
2019m2 | 7,336 1.46 85.24
2019m3 | 7,537 1.50 86.74
2019m4 | 7,438 1.48 88.23
2019m5 | 7,386 1.47 89.70
2019m6 | 7,541 1.50 91.21
2019m7 | 7,165 1.43 92.63
2019m8 | 7,311 1.46 94.09
2019m9 | 7,348 1.47 95.56
2019m10 | 7,419 1.48 97.04
2019m11 | 7,469 1.49 98.53
2019m12 | 7,378 1.47 100.00
------------+-----------------------------------
Total | 501,313 100.00
There appear to be a few thousand people each month in years 2011-2018 who were surveyed only in month 4 or 8 of their rotation group but not both.
Am I doing something wrong with the data, or are these individuals surveyed in only one of their outgoing rotation groups?