savespss - a module to export Stata data into SPSS system file format (*.sav) by Sergiy Radyakin

Description

savespss will export data from Stata's memory into an SPSS system (aka binary file) datafile (*.sav).

If instead you want to import SPSS data to Stata, then you need the -usespss- program

savespss facilitates exchange of data between Stata and SPSS. SPSS does not support direct import of datasets in recent Stata formats. Reportedly formats up to Stata 9 are supported by SPSS's import facility. SPSS of versions prior to 14.0 could not import Stata's datasets at all.

This program solves this by allowing Stata users and programmers to export their data directly in SPSS system file format.

The description of assumptions and limitations is organized into the following sections:

Supported features

savespss supports all the data attributes that the users normally expect from a statistical data conversion package, but be sure to also check the non-supported features.

List of supported features:

• numeric variables - exported as doubles without loss of precision
• short string variables (<=244 chars in all versions of Stata)
• long string variables (Stata 13.0 or newer)
• long string variables of strL type (up to the maximum length permitted by SPSS);
• long variable names (>8 chars)
• variable labels
• date/time formats (%td, %tc) and date/time correction (for difference in zero-hour);
• value labels for date/time formats;
• variable characteristics
• dataset characteristics
• system missing and extended missing values (.a, .b, .c); all other missings -> SPSS_sys_miss
• autodetection of 'convenient' per-variable mapping of extended missing values (user can specify exact values to be used for extended missing values in all variables if necessary, or switch off extended missing values all together)
• value labels (tentatively, including value labels for extended missings)
• variable formatting (only %X.Yf format is supported for numeric variables and converted to FX.Y format of SPSS, all other are written as F8.0 format of SPSS);
• variable names starting with an underscore (not supported by SPSS) - _xyz -->renamed to-->@xyz;
• codepages for non-ASCII characters, e.g Russian, German, Greek, Turkish, Arabic, and some other languages.

Not supported features and limitations

savespss supports all the data attributes that the users normally expect from a statistical data conversion package, but there are naturally some limitations.

List of [currently] not supported features:

• variable names collisions due to case insensitivity of SPSS are detected by savespss, but it is up to the user to rename the variables;
• savespss does not compress the data. There are no plans to implement data compression. Use zip to pack the output file if necessary. The resulting file will be of comparable or smaller size than the datafile in the SPSS compressed format. Note that recent versions of Stata have a built-in zip compression command zipfile. Alternatively, once the data is exported in the SPSS system file format (*.sav) it can be opened within SPSS and resaved. The option to compress the data is often the default option. .
• Stata 13 introduced long strings (strLs) with potential use as a storage for various binary resources. It is not clear whether any sequence of bytes will be treated as valid by SPSS. Furthermore, long content may be truncated on export. An attempt to recover a binary resource from truncated content may lead to unforseen consequences. What this means is that if you store a digital photograph in a strL, and it gets truncated during export, there will be only half of the picture in SPSS. An attempt to open that half in your image editor may crash the image editor. Naturally.
• savespss has been written in the times when Stata didn't support Unicode (before Stata 14.0), hence it does not expect unicode content and may produce incorrect output if the user attempts to output such content. Your best option is to convert all content to a single extended ASCII codepage, such as Arabic or Cyrillic, and then export the data in that codepage.