dr. c. ertuna1 required textbook “econometrics: by example " gujarati palgrave-macmillian...
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Dr. C. Ertuna 1
Required Textbook
“Econometrics: By Example"
Gujarati
Palgrave-Macmillian 2011
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Econometrics is set of 1.statistical and 2.mathematical tools to help to
a. prove or b. disprove
certain financial and economic i. propositions and ii. models.
What is Econometrics?
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We need to learn Econometric Techniques in order to analyze and understand financial and economic behavior in the markets.
Why do we learn Econometrics?
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How Does Econometrics Differ From Economic Theory?
• Economic theory: qualitative results — demand curves slope downward
• Econometrics: quantitative results — price elasticity of demand for milk = -0.75
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How Does Econometrics Differ From Statistics?
• Statistics: “summarize the data faithfully”; “let the data speak for themselves.”
• Econometrics: “ what do we learn from economic theory AND the data at hand?”
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What’s Metrics For?
• Estimation: What is the marginal propensity to consume?
• Hypothesis Testing: Do unions raise workers’ wages?
• Forecasting: What will Personal Savings be in 2001 if GDP is $9.2 trillion?
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Economists Ask: “What Changes What and How?”
•Higher Income, Higher Saving
•Higher Price, Lower Quantity Demanded
•Higher Interest Rate, Lower Investment
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Savings Versus Income
• Theory Would Assume an Exact Relationship, e.g., Y =X
0
1000
2000
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5000
6000
24000 48000 72000 96000
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Slope of the Line Is Key!
• Slope is the change in savings with respect to changes in income
• Slope is the derivative of savings with respect to income
• If we know the slope, we’ve quantified the relationship!
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Never So Neat: Savings Versus Income
0
1
2
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0 20 40 60 80 100 120
saving
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Yi Xi i
• We need to find best way to estimate (slope)
Econometrics helps us to find that “best way”.
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Using the Model for Prediction and Policy
Tests of Hypothesis
Specification Testing & Diagnostic Checking &
Financial or Economic Theory
Estimation
Econometric Model Data
Is the Model Adequate?Noo
Yes
Let`s get some Data
• Let`s go to the website of
Council for Economic Planning and Development.
• http://www.cepd.gov.tw/encontent/
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Let`s get some Data
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This data can be obtained fromCouncil for Economic Planning and Development http://www.cepd.gov.tw/encontent/
Taiwan Business Indicators / Business Indicators Database /Component Series /
Data Frequency Monthly
Data Period From Year: 1980 Month: 1 To Year: 2012 Month: 12
Advanced change from previous month year on year change
Leading Indicators Stock prices index
Submit
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Panel datao Cross-sectionalo Time series
Data Structure
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Raw Data
Raw data can help us in graphical form to:
• Determine the distribution (Histograms)
• Compare two or more series (processies) (Line graph)
• Observe revelation of a serie (process) (Scatterplot)
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• Trend
• Cycle
• Seasonal
• Irregularo Episodico Residual
Components of Financial or Economic Time Series
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• Growth Rates
• Changing Indices and Base• Changing Frequency (stock vs. flow var.)
• Nominal vs. Real (appropriate deflator)• Logs (linearizing trend or model, interpretation)
• Diffrencing (Stationarity)
Basic Financial or Economic Data Handling
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Growth Rates
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Discretely Compounding Growth Rates
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Discretely Compounding Growth Rates
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Continuously Compounding Growth Rates
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Continuously Compounding Growth Rates
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Basic Financial or Economic Data Handling
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• Changing Frequency (stock vs. flow var.)
Stock data: Data value at a particular time (Stock Price)
Beginning of the period
Middle of the period
End of the period
Average of the period
Flow data: Data value representing a period of timeperiodic values can be added (monthly incomes added up to
annual income)
Basic Financial or Economic Data Handling
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END
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Discretely Compounding Growth Rates
Let`s get some Data
• Let`s go to the website of
Council for Economic Planning and Development.
• http://www.cepd.gov.tw/encontent/
Statistics / Taiwan Statistical Data Book / Taiwan Statistical Data Book 2011 /
Taiwan Statistical Data Book 2011 (excel) Download
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Let`s get some Data Cont.
• In the zip file
2011.000 is the Table of Contents
• Open the zip file and take out
2011.03Worksheet 3-1 contains annual GDP of
Taiwan covering periods from 1985 to 2010.
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• Data Entry
• Graphics
• Summary Statistics
EViews
Getting Data in EViews
• File/Open/ Foreign Data as Workfile....– Follow steps
• Change Year’s data type to «Date»
• Automatically 2 new variables «c» and «residuals» are created.
• Highlight the original variables (except ‘Year’
• Wright click and choose «Open as Group»31
Summary Statistics & Graph
• View / Descriptive Stats / individual Samples
• View / Graph /
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