Hi, I found the application dataset (Data concerning pregranted patent applications) might have a left-truncation issue.
I put the tabulation tables for pregranted patent applications below. I am curious about the small numbers of applications before 2004. Is it because the AIPA just began to take effect so that there were not many publication records in early 21 century?
Also, if I want to use the pregranted patent applications data to measure patenting activities, which time range would you recommend that would suffer less from the left-truncation issue.
I would very much appreciate it if anyone could provide an explanation.
Pre-Grant Data - application dataset (Data concerning pregranted patent applications)
. tab year
year | Freq. Percent Cum.
------------+-----------------------------------
1909 | 1 0.00 0.00
1911 | 1 0.00 0.00
1913 | 1 0.00 0.00
1918 | 3 0.00 0.00
1919 | 2 0.00 0.00
1991 | 1 0.00 0.00
1994 | 2 0.00 0.00
1995 | 5 0.00 0.00
1996 | 7 0.00 0.00
1997 | 5 0.00 0.00
1998 | 4 0.00 0.00
1999 | 19 0.00 0.00
2000 | 136 0.00 0.00
2001 | 2,542 0.04 0.05
2002 | 14,519 0.26 0.30
2003 | 90,405 1.60 1.90
2004 | 232,568 4.11 6.01
2005 | 307,805 5.43 11.44
2006 | 323,546 5.71 17.15
2007 | 327,798 5.79 22.94
2008 | 316,623 5.59 28.53
2009 | 296,157 5.23 33.76
2010 | 308,004 5.44 39.20
2011 | 332,379 5.87 45.07
2012 | 354,409 6.26 51.33
2013 | 374,203 6.61 57.93
2014 | 380,919 6.73 64.66
2015 | 380,496 6.72 71.38
2016 | 380,632 6.72 78.10
2017 | 382,724 6.76 84.86
2018 | 367,383 6.49 91.34
2019 | 313,180 5.53 96.87
2020 | 177,130 3.13 100.00
------------+-----------------------------------
Total | 5,663,609 100.00
Patents Data - application (Information on the applications for granted patent).
1970 | 534 0.01 0.03
1971 | 1,181 0.02 0.04
1972 | 2,195 0.03 0.07
1973 | 8,396 0.11 0.18
1974 | 38,522 0.50 0.68
1975 | 68,052 0.88 1.56
1976 | 71,046 0.92 2.48
1977 | 71,543 0.93 3.41
1978 | 71,046 0.92 4.33
1979 | 71,120 0.92 5.25
1980 | 72,129 0.93 6.19
1981 | 69,238 0.90 7.08
1982 | 70,781 0.92 8.00
1983 | 67,612 0.88 8.88
1984 | 73,596 0.95 9.83
1985 | 78,472 1.02 10.85
1986 | 81,997 1.06 11.91
1987 | 89,163 1.16 13.06
1988 | 98,294 1.27 14.34
1989 | 104,498 1.35 15.69
1990 | 108,566 1.41 17.10
1991 | 109,592 1.42 18.52
1992 | 113,347 1.47 19.99
1993 | 118,370 1.53 21.52
1994 | 135,178 1.75 23.27
1995 | 157,411 2.04 25.31
1996 | 158,433 2.05 27.36
1997 | 184,236 2.39 29.75
1998 | 183,966 2.38 32.13
1999 | 197,162 2.55 34.69
2000 | 214,631 2.78 37.47
2001 | 228,021 2.95 40.42
2002 | 228,949 2.97 43.39
2003 | 220,572 2.86 46.25
2004 | 221,441 2.87 49.12
2005 | 226,451 2.93 52.05
2006 | 231,660 3.00 55.05
2007 | 240,202 3.11 58.16
2008 | 241,843 3.13 61.30
2009 | 233,192 3.02 64.32
2010 | 248,124 3.21 67.53
2011 | 268,408 3.48 71.01
2012 | 293,246 3.80 74.81
2013 | 311,154 4.03 78.84
2014 | 318,756 4.13 82.97
2015 | 326,432 4.23 87.20
2016 | 322,372 4.18 91.38
2017 | 296,795 3.85 95.22
2018 | 229,492 2.97 98.20
2019 | 121,352 1.57 99.77
2020 | 17,895 0.23 100.00