计量经济学-ch_01_wooldridge_5e_ppt

Chapter 1 The Nature of Econometrics and Economic Data
1.2 Steps in Empirical Economic Analysis (2/5)
Economic model of crime (Becker (1968)) Derives equation for criminal activity based on utility maximization
Average sentence
Age
length after conviction
e.g. moral character, wage in criminal activity, family background …
Chapter End © 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
Chapter End © 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
Econometric methods depend on the nature of the data used Use of inappropriate methods may lead to misleading results
Chapter End © 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
Chapter End © 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
Economic models Maybe micro- or macromodels Often use optimizing behaviour, equilibrium modeling, … Establish relationships between economic variables Examples: demand equations, pricing equations, …
Hourly wage
Years of formal education
Years of workforce experience
Weeks spent in job training
Other factors may be relevant, but these are the most important (?)
Measure of criminal activity
Wage for legal employment
Other income
Frequency of prior arrests
Unobserved determinants of criminal activity
Frequency of conviction
Typical goals of econometric analysis Estimating relationships between economic variables Testing economic theories and hypotheses Forecasting economic variables Evaluating and implementing government and business policy
Chapter 1 The Nature of Econometrics and Economic Data
1.2 Steps in Empirical Economic Analysis (1/5)
Steps in econometric analysis 1) Economic model (this step is often skipped) 2) Econometric model
Most of econometrics deals with the specification of the error Econometric models may be used for hypothesis testing
For example, the parameter represents effect of training on wage How large is this effect? Is it different from zero?
© 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
Chapter 1 The Nature of Econometrics and Economic Data
1.1 What Is Econometrics? 1.2 Steps in Empirical Economic Analysis 1.3 The Structure of Economic Data 1.4 Causality and Ceteris Paribus in Econometric Analysis Appendix A: Basic Mathematical Tools
The End © 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
Chapter 1 The Nature of Econometrics and Economic Data
1.2 Steps in Empirical Economic Analysis (5/5)
Econometric model of job training and worker productivity
Chapter 1 The Nature of Econometrics and Economic Data
1.2 Steps in Empirical Economic Analysis (3/5)
Model of job training and worker productivity What is effect of additional training on worker productivity? Formal economic theory not really needed to derive equation:
Chapter 1 The Nature of Econometrics and Economic Data
1.2 Steps in Empirical Economic Analysis (4/5)
Econometric model of criminal activity The functional form has to be specified Variables may have to be approximated by other quantities
The Nature of Econometrics and Economic Data
Chapter 1
Wooldridge: Introductory Econometrics: A Modern Approach, 5e Instructed by professor Yuan, Huiping
Chapter End © 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
Chapter 1 The Nature of a
1.1 What Is Econometrics?
What is econometrics? Econometrics = use of statistical methods to analyze economic data Econometricians typically analyze nonexperimental data
Hours spent in criminal activities
„Wage“ of criminal activities Wage for legal
employment
Other income
Probability of Probability of conviction if getting caught caught
Chapter End © 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
Hourly wage
Years of formal Years of work-
Weeks spent
education
force experience in job training
Unobserved determinants of the wage
e.g. innate ability, quality of education, family background …
Age
Expected sentence
Functional form of relationship not specified
Equation could have been postulated without economic modeling
Chapter End © 2013 Cengage Learning. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
Chapter 1 The Nature of Econometrics and Economic Data
1.3 The Structure of Economic Data (1/10)
Different kinds of economic data sets Cross-sectional data Time series data Pooled cross sections Panel/Longitudinal data