Gretl Econometric Software in Turkish

A. Talha Yalta picture 4

What is gretl?

Gretl (Gnu Regression, Econometrics, and Time-series Library) is a comprehensive and cross-platform software package for econometric analysis, being developed with the C programming language. It is free and open-source. One can freely redistribute it or modify it under the terms of the GNU General Public License (GPL) published by the Free Software Foundation. Being free makes the program ideal for the classroom environment, while being open-source software makes gretl a reliable and preferable choice in line with the principles of transparency and universality in scientific studies.

Since its relatively simple initial versions in 2000, gretl has shown a significant progress and today it has reached close to 600,000 source lines of code (SLOC). The newest versions of the program offer, in addition to an easy and intuitive user interface, a wide selection of tests and estimators, an integrated scripting language, high quality plots and many other advanced features. According to the Open HUB web site, which compiles statistics regarding various open source software projects, gretl has currently 10 active developers and contains approximately 160 human years worth of effort based on its SLOC count. Consequently, gretl's value is calculated as nearly 9 million US dollars on the basis of required resources to write the project from scratch by setting up a team of programmers with an average salary of 55,000 dollars per year.

You can find the gretl web site here, while Open HUB's gretl report page can be found here.

My contributions to gretl

gretl screenshot

I started using gretl for the first time during my economics doctoral studies in the US and, in time, I have become one of its developers. Over the years, aside from having contributions in hundreds of improvements and error corrections, I have played role in the empirical testing and documentation of gretl's linear and non-linear regression, univariate and multivariate summary statistics, statistical distributions, ANOVA, ARMA as well as random number generation functions. With A. Y. Yalta, I published in 2007 a review of the program in Journal of Applied Econometrics. As a part of this study, you can access the technical supplement which contains detailed information on the numerical accuracy of gretl. In addition, gretl is among the programs examined in my research dealing with the Box-Jenkins methodology from the econometric computation perspective, which has been published in International Journal of Forecasting in 2009. You can find the full text of this article here. Furthermore, I have been one of the organization committee members of the 2009 International gretl Conferance, which took place in May 28-29 at the Bilbao Basque Country University in Spain. In the conference, I also contributed by assessing the various statistics and regression related functions of gretl. You can download this study, entitled "Wilkinson Tests and Gretl," here. Finally, in a joint paper with S. Schreiber, I also examined the performance and reliability of the random naumber generators in gretl. You can also access this paper, which has been published in Journal of Statistical Software in 2012, here.

In 2008, I meticulously translated gretl's user interface and its website into Turkish. To accomplish this, I surveyed the various existing Turkish econometrics texts as well as the econometrical, statistical, and mathematical terms dictionaries of the Turkish Language Institute, and prepared a detailed econometric terminology renditions list. When there were multiple alternatives for a single term proposed by different authors, in order to choose the most suitable Turkish translation, I consulted with TOBB ETU Department of Turkish Language and Literature faculty members as well as various native English speaker esteemed academicians with years of service to the field of econometrics such as Fordham University Department of Economics faculty member Professor H. D. Vinod and Wake Forest University Economics Department Chair and the principal gretl developer Professor Allin Cottrell. The resulting translation, aside from being correct in terms of meaning and grammar, is also internally consistent. With this work, gretl has become the first econometric software to support the Turkish language.

I continue to update and improve the Turkish translation of gretl to this day. I am hoping that this effort will not only be useful to many Turkish scientists in their studies, but will also contribute to the development and becoming widespread of Turkish as a language of science. You can access several screenshots of gretl in Turkish here.