st: Adding observations to the beginning of a time-series or panel dataset

["Dimitriy V. Masterov" <dvmaster@gmail.com>]

I am trying to add additional time observations to the beginning of a
panel data set. I am really trying to replicate what -tsappend,
first()- would do if it existed.

Using tsappend works if you want to add data at the end, but not at
the beginning. To simplify things, tsappend1.dta is a time-series data
set that spans 1960m2 to 2000m1. The first tsappend works, while the
second does not:

#delimit;
set more off;
webuse tsappend1, clear;
tsset;

tsappend, last(2005m2) tsfmt(tm);
tsset;

tsappend, last(1955m2) tsfmt(tm);
tsset;

Any suggestions?

Dimitriy
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/