1 FE Panel Data assumptions. 2 Assumption #1: E(u it |X i1,…,X iT,  i ) = 0.

Slides:



Advertisements
Similar presentations
Econometric Analysis of Panel Data Panel Data Analysis – Random Effects Assumptions GLS Estimator Panel-Robust Variance-Covariance Matrix ML Estimator.
Advertisements

PANEL DATA 1. Dummy Variable Regression 2. LSDV Estimator
Regression with Panel Data
Data organization.
Longitudinal Data Analysis for Social Science Researchers Introduction to Panel Models
AMMBR - final stuff xtmixed (and xtreg) (checking for normality, random slopes)
AMMBR from xtreg to xtmixed (+checking for normality, random slopes)
Toolkit + “show your skills” AMMBR from xtreg to xtmixed (+checking for normality, and random slopes, and cross-classified models, and then we are almost.
SC968: Panel Data Methods for Sociologists Random coefficients models.
1 Results from hsb_subset.do. 2 Example of Kloeck problem Two-stage sample of high school sophomores 1 st school is selected, then students are picked,
Heteroskedasticity The Problem:
Lecture 4 (Chapter 4). Linear Models for Correlated Data We aim to develop a general linear model framework for longitudinal data, in which the inference.
Repeated Measures, Part 3 May, 2009 Charles E. McCulloch, Division of Biostatistics, Dept of Epidemiology and Biostatistics, UCSF.
HETEROSCEDASTICITY-CONSISTENT STANDARD ERRORS 1 Heteroscedasticity causes OLS standard errors to be biased is finite samples. However it can be demonstrated.
1 Nonlinear Regression Functions (SW Chapter 8). 2 The TestScore – STR relation looks linear (maybe)…
Advanced Panel Data Techniques
EC220 - Introduction to econometrics (chapter 7)
Multilevel Models 4 Sociology 8811, Class 26 Copyright © 2007 by Evan Schofer Do not copy or distribute without permission.
Lecture 6: Repeated Measures Analyses Elizabeth Garrett Child Psychiatry Research Methods Lecture Series.
Shall we take Solow seriously?? Empirics of growth Ania Nicińska Agnieszka Postępska Paweł Zaboklicki.
Multilevel Models 1 Sociology 229: Advanced Regression
Multilevel Models 2 Sociology 8811, Class 24
Multilevel Models 2 Sociology 229A, Class 18
Multilevel Models 1 Sociology 229A Copyright © 2008 by Evan Schofer Do not copy or distribute without permission.
Introduction to Regression Analysis Straight lines, fitted values, residual values, sums of squares, relation to the analysis of variance.
1 Review of Correlation A correlation coefficient measures the strength of a linear relation between two measurement variables. The measure is based on.
Multilevel Models 3 Sociology 8811, Class 25 Copyright © 2007 by Evan Schofer Do not copy or distribute without permission.
A trial of incentives to attend adult literacy classes Carole Torgerson, Greg Brooks, Jeremy Miles, David Torgerson Classes randomised to incentive or.
LT6: IV2 Sam Marden Question 1 & 2 We estimate the following demand equation ln(packpc) = b 0 + b 1 ln(avgprs) +u What do we require.
Returning to Consumption
Part 5: Random Effects [ 1/54] Econometric Analysis of Panel Data William Greene Department of Economics Stern School of Business.
Serial Correlation and the Housing price function Aka “Autocorrelation”
1 Estimation of constant-CV regression models Alan H. Feiveson NASA – Johnson Space Center Houston, TX SNASUG 2008 Chicago, IL.
Multilevel Analysis Kate Pickett Senior Lecturer in Epidemiology.
MULTILEVEL ANALYSIS Kate Pickett Senior Lecturer in Epidemiology SUMBER: www-users.york.ac.uk/.../Multilevel%20Analysis.ppt‎University of York.
How Does Digitization Affect Scholarship? Mark McCabe University of Michigan Roger Schonfeld Ithaka Christopher Snyder Dartmouth College December 11, 2007.
MultiCollinearity. The Nature of the Problem OLS requires that the explanatory variables are independent of error term But they may not always be independent.
Repeated Measures, Part 2 May, 2009 Charles E. McCulloch, Division of Biostatistics, Dept of Epidemiology and Biostatistics, UCSF.
Behavior in blind environmental dilemmas - An experimental study Martin Beckenkamp Max-Planck-Institute for the Research on Collective Goods Bonn – Germany.
Regression with Panel Data.  Panel Data  Panel Data with Two Periods  Fixed Effects Regression The Model Estimation Regression with Time Fixed Effects.
Lecture 3 Linear random intercept models. Example: Weight of Guinea Pigs Body weights of 48 pigs in 9 successive weeks of follow-up (Table 3.1 DLZ) The.
Biostat 200 Lecture Simple linear regression Population regression equationμ y|x = α +  x α and  are constants and are called the coefficients.
Lecture 18 Ordinal and Polytomous Logistic Regression BMTRY 701 Biostatistical Methods II.
Chapter 10 Regression with Panel Data. Outline 1. Panel Data: What and Why 2. Panel Data with Two Time Periods 3. Fixed Effects Regression 4. Regression.
Panel Data. Assembling the Data insheet using marriage-data.csv, c d u "background-data", clear d u "experience-data", clear u "wage-data", clear d reshape.
Multilevel Models 3 Sociology 229A, Class 10 Copyright © 2008 by Evan Schofer Do not copy or distribute without permission.
Lecture 5. Linear Models for Correlated Data: Inference.
STAT E100 Section Week 12- Regression. Course Review - Project due Dec 17 th, your TA. - Exam 2 make-up is Dec 5 th, practice tests have been updated.
Analysis of Experimental Data III Christoph Engel.
Modeling Multiple Source Risk Factor Data and Health Outcomes in Twins Andy Bogart, MS Jack Goldberg, PhD.
Exact Logistic Regression
1 In the Monte Carlo experiment in the previous sequence we used the rate of unemployment, U, as an instrument for w in the price inflation equation. SIMULTANEOUS.
VARIABLE MISSPECIFICATION II: INCLUSION OF AN IRRELEVANT VARIABLE In this sequence we will investigate the consequences of including an irrelevant variable.
1 Panel Data Analysis in STATA Binam Ghimire. Learning Objectives  Importing file into STATA  Running panel data regression  Run fixed, random effect.
Diff-inDiff Are exports from i to j, the same as imports in i from j? Should they be?. gen test=xij-mji (14 missing values generated). sum test,
From t-test to multilevel analyses Del-3
Chapter 15 Panel Data Models.
From t-test to multilevel analyses Del-2
Lecture 18 Matched Case Control Studies
From t-test to multilevel analyses (Linear regression, GLM, …)
Econometrics ITFD Week 8.
PANEL DATA 1. Dummy Variable Regression 2. LSDV Estimator
Introduction to Logistic Regression
QM222 Class 15 Section D1 Review for test Multicollinearity
Advanced quantitative methods for social scientists (2017–2018) LC & PVK Session 2 Multilevel analysis in Stata (with a focus on random slope models for.
Table 4. Panel Regression with Fixed Effects
Econometric Analysis of Panel Data
Financial Econometrics Fin. 505
Common Statistical Analyses Theory behind them
Modeling Multiple Source Risk Factor Data and Health Outcomes in Twins
Presentation transcript:

1 FE Panel Data assumptions

2 Assumption #1: E(u it |X i1,…,X iT,  i ) = 0

3 Assumption #2: (X i1,…,X iT,Y i1,…,Y iT ), i =1,…,n, are i.i.d. draws from their joint distribution

4 Assumption #5: corr(u it,u is |X it,X is,  i ) = 0 for t ≠s

5 Assumption #5 in a matrix:

6 Random Effects Panel Data model

7 Random Effects vs. Fixed Effects

8 Random Effects Panel Data model

9. use fatality. xtset state year panel variable: state (strongly balanced) time variable: year, 1982 to 1988 delta: 1 unit. gen vfr = mrall* xtreg vfr beertax, fe Fixed-effects (within) regression Number of obs = 336 Group variable: state Number of groups = 48 R-sq: within = Obs per group: min = 7 between = avg = 7.0 overall = max = 7 F(1,287) = corr(u_i, Xb) = Prob > F = vfr | Coef. Std. Err. t P>|t| [95% Conf. Interval] beertax | _cons | sigma_u | sigma_e | rho | (fraction of variance due to u_i) F test that all u_i=0: F(47, 287) = Prob > F = estimates store figs

10. xtreg vfr beertax, re Random-effects GLS regression Number of obs = 336 Group variable: state Number of groups = 48 R-sq: within = Obs per group: min = 7 between = avg = 7.0 overall = max = 7 Random effects u_i ~ Gaussian Wald chi2(1) = 0.18 corr(u_i, X) = 0 (assumed) Prob > chi2 = vfr | Coef. Std. Err. z P>|z| [95% Conf. Interval] beertax | _cons | sigma_u | sigma_e | rho | (fraction of variance due to u_i) estimates store rutabagas. hausman figs rutabagas ---- Coefficients ---- | (b) (B) (b-B) sqrt(diag(V_b-V_B)) | figs rutabagas Difference S.E beertax | b = consistent under Ho and Ha; obtained from xtreg B = inconsistent under Ha, efficient under Ho; obtained from xtreg Test: Ho: difference in coefficients not systematic chi2(1) = (b-B)'[(V_b-V_B)^(-1)](b-B) = Prob>chi2 =

11 What if Assumption #5 fails: so corr(u it,u is |X it,X is,  i ) ≠ 0?

12 Standard Errors under FE

13 Sampling distribution of fixed effects estimator, ctd.

14 Sampling distribution of fixed effects estimator, ctd.

15 Case I: when u it, u is uncorrelated

16 Case II: u it and u is are correlated

17 Case II: Clustered Standard Errors

18 Comments on clustered standard errors:

19 Comments on clustered standard errors, ctd.

20 Comments on clustered standard errors, ctd.

21 Implementation in STATA

22 Case II: treat u it and u is as possibly correlated

23 Try adding year effects:

24

25. xtreg vfr beertax yr2 yr3 yr4 yr5 yr6 yr7, fe vce(cluster state) Fixed-effects (within) regression Number of obs = 336 Group variable: state Number of groups = 48 R-sq: within = Obs per group: min = 7 between = avg = 7.0 overall = max = 7 F(7,47) = 4.36 corr(u_i, Xb) = Prob > F = (Std. Err. adjusted for 48 clusters in state) | Robust vfr | Coef. Std. Err. t P>|t| [95% Conf. Interval] beertax | yr2 | yr3 | yr4 | yr5 | yr6 | yr7 | _cons | sigma_u | sigma_e | rho | (fraction of variance due to u_i) Remember, we should use xtreg: Exact same as, fe robust !!! Stata version 9 incorrect! Stata 10, 11 good Stock & Watson (2008), “Heteroskedasticity-Robust Standard Errors for Fixed Effect Panel Data Regression,” Econometrica, 76 (1): 155 – 74.

26 Application: Drunk Driving Laws and Traffic Deaths (Ruhm, J. Health Econ, 1996)

27 Drunk driving laws and traffic deaths, ctd.

28

29

30 The drunk driving panel data set

31 Why might panel data help?

32

33