Hi, I have a data set like below.   ID1                    ID2 10001A              10001A             10001A            AAA111 10001A            AAA111 10001A            AAA111 10001A            AAA111 10001A 10001A 10001A   Now, I would like to fill the missing value. As long as the ID1 is the same, fill the missing value with the available value. The data set I want is below     ID1                    ID2 10001A            AAA111 10001A            AAA111 10001A            AAA111 10001A            AAA111 10001A            AAA111 10001A            AAA111 10001A            AAA111 10001A            AAA111 10001A            AAA111   Can anyone tell me what code I need to use? Thanks!   ... View more

Hi, I have a dataset like input below.   FirmID        Year        indicator 10001        1995          1 10001        1996          0 10001        1997          0 10001        1997          1 10001        1998          1 10001        1999          0 10001        1999          0 10001        1999          1 10001        2000          0 10001        2001          1   I would like to count how many 0 for each company in each year. The output is like below.   FirmID        Year         nb_Indicator_0 10001        1995                   0 10001        1996                   1 10001        1997                   1 10001        1998                   0 10001        1999                   2 10001        2000                   1 10001        2001                   0   what code do I need to use? Thanks! ... View more

Hello,   I have two datasets. The first one records the products that companies produce each year and the components for each product ("Categories" column is only for convenience and it is not in my real dataset). The second file is a component base for each year. It is updated annually as firms introduce more products. The second file has been sorted by year and components.   If all the components of a new product do not overlap with the existing component base, it will be considered as radical products. For example, Firm 10001 introduced AC449P in 1993 and its components were Y38 and I92, which do not exist in the component base before 1993 in file 2. Thus AC449P is a radical product.   If one of the components of a new product overlaps with the existing component base, it will be considered as incremental products. For example, Firm 10001 introduced AA386G in 1992 and its components were B30, V55, and T92. B30 and V55 exist in the component base before 1992 (both are in the component base of 1991). So AA386G is an incremental product.   I would like to know how many incremental products and radical products that each firm has for each year. The output that I want is below. In case you need the file, I also attached the excel file.     File 1   FirmID ProductID BeginYear Components Categories 10001 AA386G 1992 B30 Incremental 10001 AA386G 1992 V55 10001 AA386G 1992 T92 10001 AB259T 1993 R26 Incremental 10001 AB259T 1993 V55 10001 AB259T 1993 U38 10001 AC449P 1993 Y38 radical 10001 AC449P 1993 I92 10002 CT746B 1991 X48 radical 10002 CT746B 1991 K93 10002 CT746B 1991 O28 10002 RU239F 1992 A47 Incremental 10002 RU239F 1992 Q15 10002 DH469E 1993 W91 Incremental 10002 DH469E 1993 Q15 10003 CN726Q 1991 E55 radical 10003 SZ116R 1992 E55 Incremental 10003 SZ116R 1992 W87 10003 TU692E 1992 N67 Incremental 10003 TU692E 1992 I92 File 2 Year Components 1990 H32 1990 N67 1990 P99 1990 R88 1991 A47 1991 B30 1991 E55 1991 K93 1991 O28 1991 Q15 1991 V55 1991 W87 1991 X48 1992 C11 1992 T92 1992 W91 1992 Y67 1993 I92 1993 R26 1993 S23 1993 U38 1993 Y38   Output   FirmID BeginYear nb_Incremental nb_Radical 10001 1992 1 0 10001 1993 1 1 10002 1991 0 1 10002 1992 1 0 10002 1993 1 0 10003 1991 0 1 10003 1992 2 0 ... View more

Hi,   I am working on a dataset like the one below.   FirmID   ProductID  BeginYear   MarketYear   Components   dummy                 10001     AB259T      1996             1998              B30 | A           0              10001     AB259T      1996             1998              V55 | U           0            10001    AA386G      1999             2001              T92 | B            1             10001    AA386G      1999             2001              R26 | L            1            10001    AA386G      1999             2001              V55 | U           1 10002    CT746B       2007            2009              U38 | P           0 10002    CT746B       2007            2009              X48 | O           0 10002    CT746B       2007            2009              K93 | E           0 10002    RU239F       2008            2010              O28 | L           0 10002    RU239F       2008            2010              A47 | W          0 10003    TY569I         2008            2010              Q15 | P          0 10003    GC992M      2009            2011              W91 | O          1 10003    GC992M      2009            2011              Q15 | P          1   I would like to count how many zeros and ones in each year for each firm. The expected output is below.   FirmID   BeginYear   nb_ones             nb_zeros 10001      1996              0                            1 10001      1999              1                            0 10002      2007              0                            1 10002      2008              0                            1 10003      2008              0                            1 10003      2009              1                            0   nb_ones = number of ones nb_zeros = number of zeros     This dataset lists the products that are produced by each firm and their components. For example, Firm 10001 produced AB259T in 1996. B30 | A and V55 | U are both its components. So for firm 10001 in 1996, it only has one "zero" and no "one" for this company this year.   what code can I use? Thanks! ... View more