| Eco310 Econometrics | Dr. Robert Jantzen |
A Brief Guide to the EALimdep Program
| 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.
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.
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.
To select subsamples
of the data set, click on * Project * Set Sample * and
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 *. 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.
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