Eco310 Econometrics  Dr. Robert Jantzen

A Brief Guide to the EALimdep Program


Introduction
 Downloading and Installing  Preparing and Importing Excel Files
 Descriptive Statistics & Simple Plots
Ordinary Least Squares Regression
Serial (Auto)  Correlation
Heteroskedasticity
Logit Regression
Creating New Variables
Selecting Subsamples Creating Syntax Files Saving Projects

 
 
I.  Introduction

      The EALimdep regression program is a powerful freeware program available for download from the Iona College website.  It is a student version of the LIMDEP econometric program that is widely utilized in universities and industry.
 

II.  Downloading and Installing the EALimdep Program

      The EALimdep program is available for download at the following link:

       http://www.iona.edu/faculty/rjantzen/eco310/ealsetup.exe

      The MS-Word version of the manual for the program is available at:

      http://www.prenhall.com/greene/ealimdep.doc

      The Adobe Acrobat version of the manual for the program is available at:

      http://www.prenhall.com/greene/ealimdep.pdf

      Installation of the software requires two steps.  First "unzip" the EALsetup.exe file by "running" it.   Be sure to change the Unzip to Folder path to a folder that you can easily locate like the C:\Temp folder.  Second, install the EALimdep program by "running" the extracted Setup.exe file. The EALimdep program can then be started by clicking on  * Start * Run* and typing in C:\Program Files\Es\LIMDEP\Program\limdep.exe and hitting OK.

NOTE1:  for reasons unknown, the setup program creates a desktop icon named on computers running Windows XP .

NOTE2:  Because of network restrictions on Iona lab computers, the EALimdep program should be installed in a different way.  First, when running the EALsetup.exe file, change the Unzip to Folder path to U:\EALimdep so that the setup files are installed on your local U: drive.  Second, you can start the program by running the Setup.exe file contained in the U:\EALimdep folder and then clicking on Yes, Launch the Program File when it is displayed at the end of the install process.
 

III.  Preparing and Importing Excel data files

      The "recommended" way to analyze data using the EALimdep program is to first create an Excel workbook, and then "import" the data into the EALimdep program. NOTE:EALimdep will only import data from Excel workbooks that have been saved as MS Excel comma delimited file (csv) Worksheets.

      A.   To create and save data into an Excel workbook:

              i.  Start the MS-Excel program.

              ii. Either type in the data to a blank worksheet or open a saved Excel file and click on the worksheet containing the data to be imported.

              iii.  Make sure that each column of data is headed by a variable name that (a) begins with a letter and (b) is no longer than eight characters in length.

              iv.  Make sure that, aside from the column headings, all of the data consists of numbers.   EALimdep will ignore alphanumeric values so be sure to first convert categorical variables (e.g., yes, no) into numerical variables (e.g., 1, 0).  NOTE:  you can use Excel's *Edit* Replace* to do the conversion.

            v.  With the data worksheet highlighted, click on the Office Icon (top left) * Save As *, then type in a file name and click on MS Excel CSV(Comma Delimited File) as the file type.
 

       B. To import the saved Excel worksheet into the EALimdep program:

            i.  Start the EALimdep program 

            ii. Click on * Project * Import * Variables *, and then navigate to the folder containing the Excel worksheet that you want to import.   Check to see that the Excel worksheet was imported correctly by clicking on EALimdep's Data Editor icon (looks like a spreadsheet).
 

IV.  Descriptive Statistics and Simple Plots

      To obtain Descriptive Statistics, click on * Model * Data Description * *Descriptive Statistics*,  identify the variables you want statistics (mean, std.dev. and range), and then click on * Run *.    Click on the * Options * tab if you want additional statistics measuring covariance, correlation, skewness, etc.

    To obtain Simple Bivariate Plots, click on * Model * Data Description * *Plot Variables *,  identify the variables you want to plot on the X and Y axes, and then click on * Run *.
 

V.  Ordinary Least Squares Regression

      To run an Ordinary Least Squares (OLS) regression in the EALimdep program, click on * Model * * Linear Models * Regression*,  and then identify the dependent variable and independent variables.  [NOTE: Be sure to include the variable ONE as an independent variable so that EALimdep estimates a constant term.]  Then click on * Run *.  If you want to also print out the predicted values and residuals, click on the * Output * tab and click on * Display Predictions and Residuals *.
 

VI.  Testing and correcting for serial (auto) correlation

       To test and correct for serial (auto) correlation, click on * Model * Linear Models * Regression *, enter the dependent and independent variables (including ONE), and then click on * Options * * Autocorrelation * Correct for Autocorrelation using *  Cochrane - Orcutt algorithm *.  Then click on * Run *EALimdep will first generate ordinary least squares results followed by results corrected for serial (auto) correlation.
 

VII.  Testing and correcting for heteroskedasticity

        To test and correct for heteroskedasticity, click on * Model * Linear Models * Regression *, highlight the dependent and independent variables (including ONE), and then click on * Options *.  Then click on * Robust VC matrix * and then choose the * hetero HC3 * option.   Then click on      * Run *.  EALimdep will then generate the Breusch Pagan statistic as well as regression results corrected for heteroskedasticity.
 

VIII.  Logit regression models

      To generate a logit regression model on a binary dummy (1,0) dependent variable, click on *Model* * Binary Choice * Logit *,  enter the dependent and independent variables (with ONE for the constant), and then click on * Run *.  Click on the *Options* tab to generate transformed marginal effect coefficients and probability predictions.
 

IX.  Creating New Variables

        New variables can be created out of existing ones by clicking on * Project * New * Variable * and then typing in the Name of the new variable and the expression for computing it.
 

X.  Subsamples

        To select subsamples of the data set, click on * Project * Set Sample * and
then define the Range of observations that you want to include in the analyses that will follow.  You can also use the Include and Reject options to define expressions that will select/reject those cases that conform to the expression.

XI.  Creating Syntax Files

        To create a "syntax" file containing commands, click on * File * New * * Text/Command Document * OK *.  Then type in the syntax commands.  To execute, "highlight" those commands that you want EALimdep to process and click on * GO *.

XII.  Saving Projects

        If you want to save an EALimdep session for future analysis, and want to avoid re-importing the Excel data worksheet and recreating any data transformations that you've already done, then you must get EALimdep to save your project.  To do so, click on * File * Save Project As *, point to the folder where you want the project saved, and name the project.    Then you can reopen the project by starting the EALimdep program, clicking on * File * Open Project *, and then entering the saved project's name. EALimdep will recreate all of the variables that were available at the time the project was saved.