EViews Dr. Peerapat Wongchaiwat wongchaiwat@hotmail.com Todays - PowerPoint PPT Presentation

Introduction: EViews Dr. Peerapat Wongchaiwat wongchaiwat@hotmail.com

Today’s Workshop • Basic grasp of how EViews manages data • Creating Workfiles • Importing data • Running regressions • Performing basic tests • Creating/changing Series • Working with commands

Thinking About EViews • Workfile Central place to keep all of your work • Objects – Series (Numeric, no alpha series in student version) – Equations *Always comes with series for a constant, c , – Graphs and residuals, resid – Groups

Workfiles • Creating a Workfile – File → New → Workfile • Data Structure Time Series → Dated/Regular → Frequency + Date Range Cross- Sectional → Undated/Irregular → Range of observations • Save & Name (do not have to do this for this exercise) • New Pages (Eviews 6) – By clicking on the “New Page” label at the bottom of the Workfile you can create new pages • Select “By Frequency”

Importing Data • Copy/Past Method 1. Open new “Empty Group” • Quick → Empty Group • Click on Cell 1 and press the “Up” arrow on keyboard → 2. Open Excel • Make sure variable names are one constant “String” (no spaces!) • Troubleshoot for other problems 3. Copy Data 4. Paste into Eviews Cell 1

Importing Data • Import Directly 1. Count the number of variables and CLOSE Excel file 2. Proc →Import →Read Text -Locus-File 3. Browse for Excel file 4.

Descriptive Statistics • Group – Stores select series together – Object → New Object → Group → Select Series → Name • Descriptive Statistics – When group spreadsheet is open: – View → Descriptive Statistics → Common Sample → Correlogram

Regressions • Create a new Equation – In your Workfile: – Object → New Object → Equation Separated by spaces: *Dependent variable *Constant, c * Independent variables (or Group) Type of Regression Sample Range

Regression Tests & Fixes Estimate: Modify • Output Useful to Create Model Regression To Run Tests Regression Summary This View Coefficient Summary SAVE! Statistics • Name = Save to Workfile

Regression Tests & Fixes • Looking at Residuals – In Equation View: – View → Actual, Fitted, Residual → Actual, Fitted, Residual Table • Plotting Resid Vs. Fitted Values – Generate fitted values – In Equation View: “Forecast” → OK (is named “variable”f) – In Workfile: Object → New Object → Graph • Graph: resid “variable”f • Options → Type → Scatter

Regression Tests & Fixes • Heteroskedasticity – In Equation View: – View → Residual Tests → White Heteroskedasticity (no cross) – Look at Chi-square value from a table (want a small value) – Fix: Click on “Estimate” • Click on “Options” → check box for “Heteroskedasticity consistent coefficient covarariance” → OK

Regression Tests & Fixes • Normality – View → Residual Tests → Histogram -Normality Test – Look at Jarque-Bera stat (H0: Normal distribution) – Fix: Depending on skew, you can adjust variables (ex: square, log, etc) or add/delete variables

Regression Tests & Fixes • Correlation & Multicolinearity – Create Correlation Matrix: – Quick → Group Statistics → Correlations – Off-diagonal values should be less than 0.5 – Fix: Talk to your advisor

Changing/Creating Variables • Edit Mode – In Spreadsheet: Toggle “Edit+/ - ” – CAREFUL! No “undo” • Generate new variable – In Workfile: • Click on “Genr” • Enter equation: “new variable name” = equation • Regular math function keys • Lag: variable (-1)

Commands • Top, Left- Hand “Command Box” • Single commands • Batch (program) • Syntax: Command (Option) Argument

Commands • Frequently Used Commands: – show variable – genr variable = equation – sample n1 n2 • n1 and n2 represent the start and end of range • Or qualifiers such that: sample variable if >15 • Statistical Operations: – equation name .ls(h) dependent c independent variables – cor variables – group variables

Help! • For general instruction or commands: – EViews PDFs ! – Help → Users Guide (pdf) → Command & Programming Reference (pdf)

# Exercise # • Import data • Run Descriptive Statistics • Run Simple regression GDP = c + a*Cp + resid • Plot fitted values vs. residuals • Check for Heteroskedasticity and fix if necessary • Check for Multicolinearity • Check for Normality

All Done!