Synth is a statistical software that implements synthetic control methods for causal inference in comparative case studies with aggregate data as described in Abadie and Gardeazabal (2003),Abadie, Diamond, and Hainmueller(2010), and Abadie, Diamond, and Hainmueller (2013). The Synth package for R is also described in detail in Abadie,Diamond, and Hainmueller (2011). The synthetic control method allows for effect estimation in settings where a single unit (a state, country, firm, etc.) is exposed to an event or intervention. It provides a data-driven procedure to construct synthetic control units based on a convex combination of comparison units that approximates the characteristics of the unit that is exposed to the intervention. A combination of comparison units often provides a better comparison for the unit exposed to the intervention than any comparison unit alone.

Synth is available for MATLAB, Stata, and R. Feedback from users is appreciated. If you encounter a problem with the software please first check the FAQ before emailing us.

Synth for Stata
Before installing Synth, please make sure that your Stata is up to date (ie. type update all on the Stata command prompt).

To install Synth for Stata type:
ssc install synth, replace all

Synth for Stata runs on Stata versions 9-12 (32 and 64 bit), but contains a platform dependent plugin. Net install will automatically copy the correct version of the plugin to your computer. Currently, plugin versions are included for Windows platforms (XP, Vista, 7, 8) for 32 and 64 bit Stata, Mac platforms (OS X on x86-32, x86-64, PPC-32 and PPc-64) for Stata 32 or 64 bit, and Unix/Linux platforms for 32 and 64 bit Stata. If a plugin is not availbale for your platform, you will receive an error message during the installation. In this case you can email us and we can send you the C code to compile the plugin on your platform. Synth for MATLAB
– Current Version
  Synth Package for R
– To obtain the Synth package for R from CRAN typing: