Using LIMDEP 7.0 for Windows

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UsingLIMDEP 7.0 for Windows
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What is LIMDEP?

• Flexible and wide range of procedures
• Cross section data
• standard procedures
• advanced procedures
• Time series data
• standard procedures

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What is LIMDEP? (cont.)

• Basic procedures (examples)
• enter/import, create, transform data
• descriptive statistics
• single and multiple equation regression models
• cross section, time series, panel
• 2SLS, 3SLS, SURE, MLE
• logit probit models
• export output

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What is LIMDEP? (cont.)

• Advanced procedures (examples)
• nested logit models
• parametric duration models
• Poisson regression
• GMM
• stochastic frontier models
• nonlinear optimization
• write own function to be optimized

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Overview

• BASICS
• (re)opening Project
• importing data
• sample information
• output files
• saving
• creating/transforming variables
• (de)selecting variables
• plotting
• descriptive statistics
• estimating linear regression

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Overview (cont.)

• BEYOND BASICS
• estimating panel model
• (re)defining sample
• altering storage capacity
• modifying variables
• building command file
• saving correlation matrix
• exporting data
• practice

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BASICS
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Opening New LIMDEP Project

• Open LIMDEP.
• It will automatically open a new Project in a
  window titled Untitled Project 1.
• You are now ready to
• import data or
• enter data or
• open an existing LIMDEP Project.

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Re-opening Existing LIMDEP Project

• File
• Open Project
• select project
• Open

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Importing Data Files

• Project
• Import
• Variables
• Import dialog box appears
• select file to import

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Importing Data Files

• NOTE the most recent format of Excel file that
  LIMDEP will import is Excel 4.0.
• It will not import Excel files in any more recent
  format.

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Facts About Sample

• After re-open existing project containing data
  sample
• determine no. of observations in sample
• look at top of project window
• below project name
• Data U1000 Rows 99 Obs
• tells you sample contains 99 observations

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Facts About Sample (cont.)

• determine no. of variables in sample
• left click over Variables
• look at bottom of project window
• Variables 9 of 200 used
• tells you sample contains 9 variables

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Output Files

• Output from most procedures automatically goes
  to the output file.
• It appears as another window in the main LIMDEP
  screen.
• You can then
• save it
• delete it
• edit it
• cut/copy/paste to other applications.

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Editing Output File

• Output window has limited editing capability
• Might want to edit output
• add comments
• add formatting (e.g., bold, underline)

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Editing Output File (cont.)

• Steps
• Copy all or part of output in Output window
• paste into your word processing application
• edit the new file

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Exporting Output

• Save output file
• Open it using word processing application
• Can now format, cut/copy/paste, etc. as with any
  word processing file

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Saving a LIMDEP Project

• File
• Save OR
• File
• Save Project As
• type name in File name window in dialog box
• Save

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Creating New Variables /Transforming Existing
Variables Part 1

• Using Dialog Box to Enter Commands
• Project
• New
• Variable
• dialog box appears
• enter variable name in Name window
• enter expression in expression window
• OK

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Creating New Variables /Transforming Existing
Variables Part 1(cont.)

• Using Dialog Box to Enter Commands (cont.)
• NOTE some types of commands wont fit into the
  format of the dialog box for CREATE.
• In such cases, use the Text Editor.
• See Part 2

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Creating New Variables /Transforming Existing
Variables Part 2

• Using Text Editor to Enter Commands
• File
• New
• Text/Command Document
• now the Text Editing Window appears on right of
  screen.
• NOTE See CREATE command in Help for more

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Creating New Variables /Transforming Existing
Variables Part 2 (cont.)

• Using Text Editor to Enter Commands (cont.)
• Options in Text Editing Window
• type commands
• AND / OR
• insert full contents of a text file containing
  LIMDEP commands
• Insert, Text File
• select the file

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Creating New Variables /Transforming Existing
Variables Part 2 (cont.)

• Using Text Editor to Enter Commands (cont.)
• When ready to execute commands
• highlight the lines you want to execute
• Options
• press Go button on toolbar
• OR
• Run, select either Run or Run Multiple Times

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Selecting Variables in Dialog Boxes

• One variable at a time -
• highlight variable in variable list box
• select ltlt button
• repeat for one variable at a time until done.

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Selecting Variables in Dialog Boxes (cont.)

• Multiple variables at one time
• highlight each variable in variable list box
  while pressing CTRL key
• select ltlt button.
• OR . . . (next slide)

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Selecting Multiple Variables (cont.)

• highlight first variable in variable list box
• highlight last variable in variable list box
  while pressing SHIFT key
• select ltlt button.

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Selecting Variables in Dialog Boxes (cont.)

• Reversing any of the above
• after highlight variable(s)
• select gtgt button

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Plotting Variables

• Model
• Data Description
• Plot Variables
• enter variable name for X axis
• enter variable name for Y axis
• click Options tab to select any options you want
• Run

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Descriptive Statistics

• Model
• Data Description
• Descriptive Statistics
• in DSTATS dialog box, select variables for
  descriptive statistics
• click on Options tab
• select any option(s) you want
• select Run button

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Estimating Linear Regression Model

• Model
• Linear Models
• Regression
• select Dependent variable
• select Independent variables

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Estimating Linear Regression Model (cont.)

• For basic set of results, select Run
• Many other options under Options and Output.
• Can select these before selecting Run

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BEYOND BASICS
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Estimating Panel Model

• Model, Linear Models
• Regression
• select Dependent variable
• select independent variables
• select Options tab
• select Panel Data model
• select Stratify using variable
• select the stratification variable

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Estimating Panel Model (cont.)

• For basic set of results, select Run
• Many other options under Options and Output
• Can select these before selecting Run

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Defining Current Sample

• Project
• Set Sample

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Defining Current Sample (cont.)

• Several selections available
• All all observations in sample
• Range enter either single observation no. or
  range(s) of observation nos.
• Include enter an expression
• example AGE gt 15
• Reject enter an expression
• example AGE ? 0

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Modifying Data Storage Capacity

• Can alter several characteristics of data storage
  capacity
• max no. of data values
• max no. of observations
• max no. of variables
• Project, Settings
• select Data Area tab
• DO THIS BEFORE HAVE DATA IN AN OPEN PROJECT

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Modifying Variables in Project

• Open project
• Right click over variable name
• Can now
• Edit
• Rename
• Sort
• Copy Name
• Delete

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Building a Command File

• Suppose you will be executing the same set of
  commands many times with few/no changes each
  iteration
• Can use the menus each time
• could become lengthy process
• OR can use a command file
• could be quicker

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Building Command File (cont.)

• One beauty of LIMDEP is that you do NOT need to
  learn LIMDEPs commands to build a command file
• Each executed command is echoed in the output
  file

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Building Command File (cont.)

• You can simply cut/copy/paste commands from the
  output file into a new file
• see Editing Output File slide
• Use that new file as command file

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Building Command File (cont.)

• See these sections in LIMDEP Help file
• 3.3. LIMDEP Commands
• 3.4. Submitting Commands Using the Editor and
  input Files
• 3.5. Program Output and the Output Window

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Saving Correlation Matrix

• Double click box containing Matrix COR.MAT
• Edit
• Select All
• Edit
• Copy
• go to application where youll copy this matrix
• Paste

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Saving Correlation Matrix (cont.)

• NOTE can paste into Excel or Word or whatever.
• Pasting matrices into Excel allows quicker
  formatting such as
• fitting to one page
• making output more readable, etc.

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Exporting (Data) Files

• Option 1
• Project
• Export
• Variables
• fill in windows in dialog box

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Exporting (Data) Files (cont.)

• Option 2
• Project, Data Editor
• Edit, Select All
• Edit, Copy
• go to whichever application you will export data
  into
• select location for copy
• paste

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Practice Exercise

• Complete each step in the following practice
  exercise
• Compare your results at each step with the
  results shown on the following slides

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Practice Exercise (cont.)
DISPINC disposable personal income PERSCONS
personal consumption expenditures DUMMY
indicator for selected years
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Step 1

• Create an Excel file containing the data shown on
  the previous slide
• Save it as EXCEL 4 FILE
• Import it into LIMDEP
• Save the project
• name it LIMDEP Practice

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Step 1 Result
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Step 2

• Plot YEAR (on horizontal - x axis) against
  DISPINC
• select option connect data points with lines
• Plot YEAR (on horizontal - x axis) against
  PERSCONS
• select option connect data points with lines

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Step 2 Result
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Step 2 Result (cont.)
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Step 3

• Calculate descriptive statistics for all four
  variables in your sample, including a correlation
  matrix

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Step 3 Result

Descriptive Statistics
All results based on nonmissing
observations. Variable Mean
Std.Dev. Minimum Maximum
Cases ------------------------------------------
--------------------------------------------------
------ YEAR 1974.50000
3.02765035 1970.00000 1979.00000
10 DISPINC 879.240000 86.4050179
751.600000 1015.70000 10 PERSCONS
793.430000 84.9654315 672.100000
927.600000 10 DUMMY .400000000
.516397779 .000000000 1.00000000
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Matrix COR.MAT. has 4 rows and 4 columns.
YEAR DISPINC
PERSCONS DUMMY ---------------------
--------------------------------------------------
---------------------- YEAR
.1000000D01 .9876668D00 .9853315D00
.8528029D00 DISPINC .9876668D00
.1000000D01 .9958588D00 .8397949D00 PERSCONS
.9853315D00 .9958588D00 .1000000D01
.8723582D00 DUMMY .8528029D00
.8397949D00 .8723582D00 .1000000D01
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Step 4

• Define a subset of the sample as only those
  observations in 1975-1979
• Calculate descriptive statistics for all four
  variables in your sample, including a correlation
  matrix

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Step 4 Result
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Step 4 Result

Descriptive Statistics
All results based on nonmissing
observations. Variable Mean
Std.Dev. Minimum Maximum
Cases ------------------------------------------
--------------------------------------------------
------ YEAR 1977.00000 1.58113883
1975.00000 1979.00000
5 DISPINC 945.820000 57.6437941
874.900000 1015.70000 5 PERSCONS
859.520000 59.8149396 779.400000
927.600000 5 DUMMY .800000000
.447213595 .000000000 1.00000000
5
Matrix COR.MAT. has 4 rows and 4 columns.
YEAR DISPINC
PERSCONS DUMMY ---------------------
--------------------------------------------------
---------------------- YEAR
.1000000D01 .9973356D00 .9952343D00
.7071068D00 DISPINC .9973356D00
.1000000D01 .9950853D00 .6877668D00 PERSCONS
.9952343D00 .9950853D00 .1000000D01
.7487835D00 DUMMY .7071068D00
.6877668D00 .7487835D00 .1000000D01
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Step 5

• Redefine the sample to all observations
• Create a new variable using the dialog box
• CONSDUM PERSCONDUMMY
• Create a new variable using the text editor
• INCDUM DISPINCDUMMY

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Step 5 Result
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Step 5 Result (cont.)
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Step 6

• Regress PERSCONS (DV) on DISPINC INCDUM
• use the REGRESS command
• ALWAYS include ONE

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Step 6 Result
-------------------------------------------------
---------------------- Ordinary least
squares regression Weighting variable none
Dep. var. PERSCONS Mean 793.4300000
, S.D. 84.96543153 Model size
Observations 10, Parameters 3,
Deg.Fr. 7 Residuals Sum of squares
231.9503620 , Std.Dev. 5.75637
Fit R-squared .996430, Adjusted
R-squared .99541 Model test F
2, 7 976.89, Prob value
.00000 Diagnostic Log-L -29.9091,
Restricted(b0) Log-L -58.0850
LogAmemiyaPrCrt. 3.763, Akaike Info. Crt.
6.582 Autocorrel Durbin-Watson
Statistic 2.40024, Rho -.20012
-----------------------------------------------
------------------------ ----------------------
--------------------------------------------
Variable Coefficient Standard Error
t-ratio PTgtt Mean of X ----------------
----------------------------------------------
---- Constant 22.02492142 35.449853
.621 .5541 DISPINC .8674311681
.43031505E-01 20.158 .0000 879.24000 INCDUM
.2263737821E-01 .74607995E-02 3.034
.0190 385.42000