New features in the Stata time series library
---------------------------------------------

This help file describes new and modified features in the Stata time series
library.  The file is cumulative; it begins with the changes added in the
most recent STB distribution diskette.  Older changes follow.  Type ^help ts^
for general information on the time series library.
 

Changes in STB-24
-----------------
^tspred^ has been upgraded to a level A program.  In addition, four new 
programs have been added to assist in producing forecasts.  The new programs
are: ^date2obs^, ^filldate^, ^projdate^, and ^scenario^.  The most significant
addition is ^scenario^, which creates user-defined scenarios for RHS variables.


Changes in STB-23
-----------------
An improved version of Ken Heinecke's ^hansen^ program (sts8) has been 
added.


Changes in STB-22
-----------------
The time series library was upgraded to recognize panel data, that is,
a mixture of time series and cross section data.   A new command, ^csunits^,
was added to identify the cross-sectional indexes.  ^csunits^ is the 
cross section analog of ^datevars^.

The ^lag^ command was also upgraded to recognize panel data.  As a side
effect, ^lag^ is now somewhat more "invasive".  ^lag^ will sort the data,
if necessary, to insure the data are stored in correct time order before
lags are calculated.

Most of the time series commands are not yet upgraded to handle panel data.
These commands are:

        ^ac^, ^chow^, ^dif^, ^finddate^, ^findsmpl^, ^growth^
        ^pac^, ^quandt^, ^regdiag^, ^tspred^, and ^xcorr^.

Note that ^tsfit^ and ^tsreg^ should correctly estimate models for panel
data.  However, the reporting of sample information and some of the 
regression diagnostics are incorrect.

In ordinary (non-panel) time series data, all commands work as before.


Changes in STB-20
-----------------

Alan Riley's (dm20) date commands have been added to the time series library.
These programs include:

^downame^: converts a day-of-the-week code to a name.
^lastday^: calculates the last day of the month.
^lstbday^: calculates the last business day of the month.
^mdytodow^: calculates the day of the week from month/day/year.
^mnthname^: converts a month code to a name.
^namedow^: converts a name to a day-of-the-week code.
^namemnth^: converts a name to a month code.
^today^: calculates today.
^ystrday^: calculates yesterday from today.


Changes in STB-19
-----------------

^findsmpl^: findsmpl would fail if there were no usable observations.  This 
    bug has been corrected.  findsmpl now reports "no observations" and 
    returns without an error.

^growthi^: growthi is an immediate form of growth.ado.  


Changes in STB-18
-----------------

^faketemp^:  faketemp.ado (STB-17: ip5) has been added to the library.  This
    program was written by Craig Hakkio, Federal Reserve Bank of Kansas City. 
    Type "help faketemp" for more information.

^lag^:  The ^lag^ command has been substantially rewritten and the syntax has
    been expanded to permit variable lists.  The ^lag^ command is also smarter
    about combining operators.  The ^lead^ and ^dif^ commands will be revised
    along the same lines in later issues.

^regdiag^:  The Durbin-Watson statistic was occasionally misreported as a 
    missing value.  This bug has been fixed.  A new option, ^time^, has been
    added.  The ^time^ option specifies a standard selection of time series 
    diagnostics.  This set includes Akaike's Information Criterion (^aic^), 
    the ARCH test (^arch^), the Durbin-Watson test (^dw^), the LM (^lm^) and
    Q (^q^) tests for serial correlation, the Schwarz criterion (^sc^), and the
    test of the normality of the residuals (^normal^).

^tauprob^:  tauprob.ado (STB-17: sts6) has been added to the library.  This
    program was written by Craig Hakkio, Federal Reserve Bank of Kansas City. 
    Type "help tauprob" for more information.

^tsreg^:  ^tsreg^ now displays the standard set of time series diagnostics 
    (see ^regdiag^ above) rather than all possible diagnostics.