Hi All,

A snippet of my data resembles the following:


Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input float(year y x)
1990 121 123
1990 213 123
1990 213   3
1990   3  12
1990   1  23
1990   1 123
1990   4 123
1991  23 123
1991   3 123
1991  12 123
1991 123 123
1991 123   1
1991 123   3
1991  12 313
1991  32 123
end
Although the above contains just 1990-1991, my actual data extends from 1850-2010.
What I wish to do, is to graph the coefficient on x by year, along with the confidence interval bands. I am presently using the following code:

Code:
forvalues i = 1990/1991 {     
    regress y x if year == `i'
    estimates store year`i'
    local allyears `allyears' year`i'  ||
    local labels `labels' `i'
}
Following this, the coef plot comes in handy:

Code:
coefplot `allyears', keep(x) vertical bycoefs bylabels(`labels')
Now, when I verify whether the local variable stored values correctly, I use the command:

Code:
display "`allyears'"
Indeed, when the dataset only contains 1990 and 1991, both the coeplot function, as well as the local variable works as expected. However, when I use the exact same command for the entire dataset, displaying the local variable results in a blank, which then results in the coefplot command also not displaying anything. Is there any reason why the exact same commands don't work for a bigger dataset? Is there a limit on the number of values that can be stored in the local variable?

Any help on this is much appreciated.


CS