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st: RE: How do I create a calendar year variable by person id before reshaping to person-year dataset?


From   Holly E Reed <[email protected]>
To   "[email protected]" <[email protected]>
Subject   st: RE: How do I create a calendar year variable by person id before reshaping to person-year dataset?
Date   Fri, 7 Feb 2014 16:34:41 +0000

Hi,

I am trying to create a person-year dataset for use in a binomial logit event history model.  I want to have one observation for each year of a person's life (one record per person-year), but I also need the calendar years as the variables, so that I can create covariates such as whether a woman had a birth in a particular year (0/1 dummy), whether a woman moved in a particular year (0/1 dummy), etc.  There will be some non-time-varying covariates, of course, but for the data where I do have time covariance, I want to create dummies for events in each specific year.

I will probably create parity as a covariate also, as Steve mentions, but the main question of interest is whether a woman gives birth in a particular year (this will be lagged by one year) and whether that predicts the probability of migration in the next year.

Does that make sense?  If you have a better suggestion, please let me know.  I did create a migration dataset from this same data several years ago, but I did not have the birth data at the time and I simply want to merge it with the migration dataset I already have, but I need it to be in the same format and I can't seem to get it work the way it did the last time.

Thanks,
Holly
______________
As you point out, Nick, Holly has not told us what she wants to do. I'm
not sure either, as she's tried reshapes both long and wide. 

I've analyzed many data sets of reproductive histories, and I always use
the long format. With this format, it's easy to create running totals of
different kinds, for example parity, the number of births + stillbirths
at a given time. We also can merge in dates of different risk factor
exposures and so easily assign a prior or recent exposure to each
pregnancy. In fact, we always *collect* the data in long format,
as it shortens the codebook and greatly simplifies the edit process. It
also allows a woman to recall a pregnancy out of order, because one
can re-order by date.

Steve
[email protected]


On Feb 6, 2014, at 6:14 PM, Nick Cox <[email protected]> wrote:

Thanks. That helps. I have already explained why -reshape wide-
doesn't work. -reshape- maps one variable to several, but the "birth"
you feed to it is the stub for several variables.

Otherwise, I don't see why you want or need to -reshape- at all.
Several variables are repeated for each woman and some vary. Depending
on what you want to do, you either reduce the dataset by removing
duplicates or keep the whole dataset.

Alternatively, if you explain why you (think you) need to -reshape-
that might illuminate what is being misunderstood, or what you need to
do.
Nick
[email protected]
__________________________
From: Holly E Reed
Sent: Thursday, February 06, 2014 3:31 PM
To: [email protected]
Subject: Re: How do I create a calendar year variable by person id before reshaping to person-year dataset?

Hi Nick,

Here is an extract from the dataset:

i_weight    masterid  birth1  birth2  birth3  birth4  hhid  id  provage12  urbanage12  evermig  relation              sex  age  cyear1  cyear2  cyear 3  yrbirth  yrdate
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1979
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1980
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1981
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1982
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1983
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1984
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1985
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1986
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1987
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1988
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1989
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1990
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1991
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1992
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1993
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1994
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1995
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1996
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1997
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1998
37.64478   43           1998  .         .         .          4     17  "E Cape"   "Rural"         1           "Son/Daughter"   "F"  21    1908    1909     1910      1979    1999
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1982
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1983
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1984
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1985
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1986
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1987
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1988
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1989
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1990
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1991
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1992
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1993
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1994
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1995
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1996
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1997
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1998
37.64478   54           .        .         .         .          5     23  "W Cape"  "Urban"        0           "Son/Daughter"   "F"  18    1908    1909     1910      1982    1999
37.64478   111         1955  1959   1964  1966    11    51   "E Cape"   "Rural"        1            "Head"               "F"  67    1908    1909     1910      1933    1933
37.64478   111         1955  1959   1964  1966    11    51   "E Cape"   "Rural"        1            "Head"               "F"  67    1908    1909     1910      1933    1934
37.64478   111         1955  1959   1964  1966    11    51   "E Cape"   "Rural"        1            "Head"               "F"  67    1908    1909     1910      1933    1935
37.64478   111         1955  1959   1964  1966    11    51   "E Cape"   "Rural"        1            "Head"               "F"  67    1908    1909     1910      1933    1936
37.64478   111         1955  1959   1964  1966    11    51   "E Cape"   "Rural"        1            "Head"               "F"  67    1908    1909     1910      1933    1937
37.64478   111         1955  1959   1964  1966    11    51   "E Cape"   "Rural"        1            "Head"               "F"  67    1908    1909     1910      1933    1938
37.64478   111         1955  1959   1964  1966    11    51   "E Cape"   "Rural"        1            "Head"               "F"  67    1908    1909     1910      1933    1939
37.64478   111         1955  1959   1964  1966    11    51   "E Cape"   "Rural"        1            "Head"               "F"  67    1908    1909     1910      1933    1940

And so on...So these are three women, first is age 21, with one birth in 1998; second is age 18, with no births; third is 67 years old, with four births (she actually had seven, but I didn't show all birth* variables here to save space) in 1955, 1959, 1964, and 1966.

I only listed birth1-birth4, but in fact there are birth 1-birth10 which follow along the same lines.  Also cyear1-cyear93 are in the dataset; same for each person and each year 1908-2000.

In terms of code, I have tried three iterations of coding for the reshape command:

reshape long birth, i(id) j(year)

reshape long birth cyear, i(id) j(year)

AND
reshape wide birth, i(id) j(year)

Hoping that this helps to clarify things a bit...any ideas?

Thanks,
Holly
_______________________________________________


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