Hello, I need help with two merging panel data sets according to the following variables: h_id, year, g_m1 and gender_m.

The form that I want to achieve by merging is something like:
h_id h_pid year g_m1 gender_m c_age c_age
15 1502 2017 20 1 8 12

The problems that I am facing is that stata says that the variables do not uniquely identify observations in the master data. (I can't understand why they are not unique.)

Another is it's 1:m merging. (because the master data set is observations of parents and the using data set are children - and I want to match children to parents)

I'm sorry i made the explanation very confusing but it'd be really appreciated if I can get some help/ idea to get through this. I have attached the datasets below. Please let me know if you need further explanation/ information. Thank you.


The below is the master data set.
Code:
* Example generated by -dataex-. For more info, type help dataex
clear
input int h_id long h_pid float(year age g_m1 gender_m)
15 1502 2017 42 20 1
15 1502 2005 30 20 1
15 1501 2020 42 10 0
15 1501 2012 34 10 0
15 1501 2008 30 10 0
15 1501 2011 33 10 0
15 1502 2014 39 20 1
15 1502 2015 40 20 1
15 1502 2018 43 20 1
15 1502 2008 33 20 1
15 1501 2018 40 10 0
15 1502 2016 41 20 1
15 1502 2013 38 20 1
15 1501 2010 32 10 0
15 1501 2013 35 10 0
15 1502 2007 32 20 1
15 1501 2015 37 10 0
15 1501 2009 31 10 0
15 1501 2007 29 10 0
15 1501 2014 36 10 0
15 1502 2012 37 20 1
15 1502 2006 31 20 1
15 1502 2011 36 20 1
15 1501 2016 38 10 0
15 1501 2005 27 10 0
15 1502 2010 35 20 1
15 1501 2017 39 10 0
15 1502 2019 44 20 1
15 1501 2019 41 10 0
15 1502 2009 34 20 1
15 1502 2020 45 20 1
15 1501 2006 28 10 0
38 3801 2020 48 10 0
38 3801 2010 38 10 0
38 3802 2005 31 20 1
38 3801 2006 34 10 0
38 3801 2014 42 10 0
38 3802 2011 37 20 1
38 3802 2014 40 20 1
38 3801 2016 44 10 0
38 3802 2016 42 20 1
38 3801 2009 37 10 0
38 3802 2017 43 20 1
38 3801 2019 47 10 0
38 3802 2009 35 20 1
38 3802 2018 44 20 1
38 3801 2012 40 10 0
38 3801 2017 45 10 0
38 3802 2010 36 20 1
38 3801 2011 39 10 0
38 3802 2015 41 20 1
38 3802 2008 34 20 1
38 3802 2013 39 20 1
38 3801 2008 36 10 0
38 3802 2012 38 20 1
38 3801 2005 33 10 0
38 3801 2018 46 10 0
38 3802 2019 45 20 1
38 3801 2007 35 10 0
38 3801 2013 41 10 0
38 3802 2007 33 20 1
38 3801 2015 43 10 0
38 3802 2020 46 20 1
38 3802 2006 32 20 1
45 4501 2013 41 10 0
45 4502 2015 42 20 1
45 4501 2010 38 10 0
45 4501 2005 33 10 0
45 4501 2011 39 10 0
45 4502 2012 39 20 1
45 4501 2016 44 10 0
45 4502 2011 38 20 1
45 4502 2008 35 20 1
45 4502 2016 43 20 1
45 4501 2007 35 10 0
45 4501 2006 34 10 0
45 4501 2020 48 10 0
45 4501 2019 47 10 0
45 4501 2009 37 10 0
45 4502 2005 32 20 1
45 4502 2013 40 20 1
45 4502 2010 37 20 1
45 4502 2009 36 20 1
45 4501 2018 46 10 0
45 4501 2014 42 10 0
45 4502 2019 46 20 1
45 4502 2007 34 20 1
45 4501 2008 36 10 0
45 4501 2015 43 10 0
45 4502 2017 44 20 1
45 4502 2018 45 20 1
45 4501 2017 45 10 0
45 4502 2006 33 20 1
45 4502 2014 41 20 1
45 4501 2012 40 10 0
45 4502 2020 47 20 1
48 4802 2017 35 20 1
48 4805 2018 42 10 0
48 4801 2007 73 10 1
48 4802 2011 29 20 1
end
And the below is the using data set that I want to merge into the master data set.

Code:
* Example generated by -dataex-. For more info, type help dataex
clear
input int h_id float(year g_m2 gender_m c_age)
15 2018 20 1 14
15 2015 20 1 11
15 2012 20 1  8
15 2016 20 1  8
15 2014 20 1  6
15 2008 20 1  4
15 2017 20 1  9
15 2006 20 1  2
15 2016 20 1 12
15 2013 20 1  9
15 2005 20 1  1
15 2009 20 1  5
15 2017 20 1 13
15 2020 20 1 16
15 2011 20 1  7
15 2010 20 1  2
15 2014 20 1 10
15 2019 20 1 11
15 2009 20 1  1
15 2007 20 1  3
15 2015 20 1  7
15 2012 20 1  4
15 2010 20 1  6
15 2019 20 1 15
15 2018 20 1 10
15 2013 20 1  5
15 2011 20 1  3
15 2020 20 1 12
38 2014 20 1  8
38 2018 20 1 12
38 2012 20 1  6
38 2008 20 1  2
38 2011 20 1  5
38 2019 20 1 13
38 2013 20 1  7
38 2016 20 1 10
38 2009 20 1  3
38 2010 20 1  4
38 2014 20 1  8
38 2007 20 1  1
38 2007 20 1  1
38 2015 20 1  9
38 2016 20 1 10
38 2015 20 1  9
38 2013 20 1  7
38 2020 20 1 14
38 2010 20 1  4
38 2019 20 1 13
38 2018 20 1 12
38 2017 20 1 11
38 2008 20 1  2
38 2012 20 1  6
38 2011 20 1  5
38 2017 20 1 11
38 2020 20 1 14
38 2009 20 1  3
45 2012 20 1  8
45 2007 20 1  3
45 2015 20 1 11
45 2018 20 1 14
45 2010 20 1  6
45 2017 20 1 13
45 2011 20 1  7
45 2006 20 1  2
45 2005 20 1  1
45 2013 20 1  9
45 2020 20 1 16
45 2008 20 1  4
45 2019 20 1 15
45 2016 20 1 12
45 2014 20 1 10
45 2009 20 1  5
48 2014 20 1  4
48 2011 20 1  1
48 2018 20 1  8
48 2017 20 1  5
48 2016 20 1  6
48 2013 20 1  3
48 2020 20 1  8
48 2012 20 1  2
48 2018 20 1  6
48 2013 20 1  1
48 2017 20 1  7
48 2014 20 1  2
48 2015 20 1  3
48 2016 20 1  4
48 2019 20 1  9
48 2019 20 1  7
48 2015 20 1  5
48 2020 20 1 10
end