Suggested Reading for June

• Colussi, T., 2018. Social ties in academia: A friend is a treasure. Review of Economics and Statistics, 100, 45-50.
• Dette, H., K. Möllenhoff, S. Volgushev, & F. Bretz, 2018. Equivalence of regression curves. Journal of the American Statistical Association, online.
• Kumbhaker, S. C., C. F. Parmeter, & V. Zelenyuk, 2018. Stochastic frontier analysis: Foundations and advances. Working paper No. WP02/2018, Centre for Efficiency and productivity Analysis, School of Economics, University of Queensland.
• Morshed, A. A., E. Andreou, & O. Boldea, 2018. Structural break tests robust to regression misspecification. Econometrics, 6, 27.
• Zhang, L., 2018. Spurious regressions with high-order models: A reconsideration. Economics Letters, 168, 70-72.
• Zhao, S., A. Ullah, & X. Zhang, 2018. A class of model averaging estimators. Working Paper Series 18-11, Rimini Centre for Economic Analysis.

© 2018, David E. Giles

The Uniqueness of the Cointegrating Vector

Suppose that we have (only) two non-stationary time-series, X_1t and X_2t (t = 1, 2, 3, .....). More specifically, suppose that both of these series are integrated of order one (i.e., I(1)). Then there are two possibilities - either X₁ and X₂ are cointegrated, or they aren't.

You'll recall that if they are cointegrated, then there is a linear combination of X₁ and X₂ that is stationary. Let's write this linear combination as Z_t = (X_1t + αX_2t). (We can normalize the first "weight" to the value "one" without any loss of generality.) The vector whose elements are 1 and α is the so-called "cointegrating vector".

You may be aware that if such a vector exists, then it is unique.

Recently, I was asked for a simple proof of this uniqueness. Here goes.........

Results of the Econometric Game, 2018

In a recent post I mentioned the 2018 "edition" of The Econometric Game, which was held in Amsterdam earlier this month.

In random order, the finalists, after the first two days' of competition, were the teams representing:

Aarhus University
Erasmus Universiteit Rotterdam
Harvard University
Lund University
McGill University
Universiteit van Tilburg
Universiteit van Amsterdam
University Carlos III Madrid
University of Bristol
University of Toronto

These teams then competed in a further one-day event..

The team from University Carlos III Madrid emerged the winner; with those from Harvard University and Aarhus University taking second and third places respectively.

The organizers of The Game have provided a gallery of photos. here   

Congratulations to all involved for another impressive event!

© 2018, David E. Giles

April Reading

Very belatedly, here is my list of suggested reading for April:

• Biørn, E., 2017. Identification, instruments, omitted variables, and rudimentary models: Fallacies in the "experimental approach" to econometrics. Memorandum No. 13/2017, Department of Economics, Oslo University.
• Chambers, M. J., and M. Kyriacou, 2018. Jackknife bias reduction in the presence of a near-unit root. Econometrics, 6, 11.
• Derryberry, D., K. Aho, J. Edwards, and T. Peterson, 2018. Model selection and regression t-statistics. American Statistician, in press.
• Mitchell, J., D. Robertson, and S. Wright, 2018. R² bounds for predictive models: What univariate properties tell us about multivariate predictability. Journal of Business and Economic Statistics, in press. (Free download here.)
• Parker, T., 2017. Finite-sample distributions of the Wald, likelihood ratio, and Lagrange multiplier test statistics in the classical linear model. Communications in Statistics - Theory and Methods, 46, 5195-5202.
• Troster, V., 2018. Testing Granger-causality in quantiles. Econometric Reviews, 37, 850-866.

© 2018, David E. Giles

The (Undergraduate) (Econo) Metrics Game

In a comment on my recent post about the long-running Econometrics Game for graduate student teams, "BJH" kindly pointed out the existence of a counterpart for undergraduate econometrics students.

The "Metrics Game" is a two-day competition organised by OEconomica in association with the University of Chicago’s Department of Economics and the Becker Friedman Institute. 

The 2018 competition is the fourth in the series, and gets underway on 7 April at the University of Chicago.

It's great to see competitions of this type being made available for students at all levels of study.

© 2018, David E. Giles

The Econometric Game, 2018

Readers of this blog will be familiar with The Econometric Game. You'll find my posts about the 2016 and 2017 Games here, and here the first of those posts links to ones about the Games from previous years.

The Econometric Game is a competition between teams of graduate students in econometrics. It's organised by the study association for Actuarial Science, Econometrics & Operational Research (VSAE) of the University of Amsterdam, and it has been a terrific success.

The Econometric Game has been held annually since 1999. This year, 30 teams have been chosen to compete in the Games, which will be held in Amsterdam from 11 to 13 of April. The theme for this year's competition is "Econometrics of Happiness".

The winners in both 2016 and 2017 were teams representing Harvard University. Let's see how they perform this year. I'll have some follow-up posts once the Game gets underway next month.

© 2018, David E. Giles

March Reading List

• Annen, K. & S. Kosempel, 2018. Why aid-to-GDP ratios? Discussion Paper 2018-01, Department of Economics and Finance, University of Guelph.
• Conover, W. J., A. J. Guerrero-Serrano, & V. G. Tercero-Gomez, 2018. An update on 'a comparative study of tests for homogeneity of variance'. Journal of Statistical Computation and Simulation, online.
• Foroni, C., M. Marcellino, & D. Stevanović, 2018. Mixed frequency models with MA components. Discussion Paper  No. 02/2018, Deutsche Bundesbank.
• Sen, A., 2018. Lagrange multiplier unit root test in the presence of a break in the innovation variance. Communications in Statistics - Theory and Methods, 47, 1580-1596.
• Stewart, K. G., 2018. Suits' watermelon model: The missing simultaneous equations empirical example. Mimeo., Department of Economics, University of Victoria.
• Weigt, T. & B. Wilfling, 2018. An approach to increasing forecast-combination accuracy through VAR error modeling. Paper 68/2018, Department of Economics, University of Münster.

© 2018, David E. Giles

Recommended Reading for February

Here are some reading suggestions:

• Bruns, S. B., Z. Csereklyei, & D. I. Stern, 2018. A multicointegration model of global climate change. Discussion Paper No. 336, Center for European, Governance and Economic Development Research, University of Goettingen.
• Catania, L. & S. Grassi, 2017. Modelling crypto-currencies financial time-series. CEIS Tor Vegata, Research Paper Series, Vol. 15, Issue 8, No. 417.
• Farbmacher, H., R. Guber, & J. Vikström, 2018. Increasing the credibility of the twin birth instrument. Journal of Applied Econometrics, online.
• Liao, J. G. & A. Berg, 2018. Sharpening Jensen's inequality. American Statistician, online.
• Reschenhofer, E., 2018. Heteroscedasticity-robust estimation of autocorrelation. Communications in Statistics - Simulation and Computation, online.

© 2018, David E. Giles

Economic Goodness-of-Fit

What do we mean by a "significant result" in econometrics?

The distinction between "statistical significance" and "economic significance" has received a good deal of attention in the literature. And rightly so.

Think about the estimated coefficients in a regression model, for example. Putting aside the important issue of the choice of a significance level when considering statistical significance, we all know that results that are significant in the latter sense may or may not be 'significant' when their economic impact is considered.

Marc Bellemare provided a great discussion of this in his blog a while back.

Here, I want to draw attention to a somewhat related issue - distinguishing between the statistical and economic overall goodness-of-fit of an economic model.

ASA Symposium on Statistical Inference - Recorded Sessions

In October of last year, the American Statistical Association held a two-day Symposium on Statistical Inference in Bethesda, MD.

The symposium was sub-titled, Scientific Method for the 21st. Century: A World Beyond p < 0.05. That gives you some idea of what it was about.

The ASA has now released video recordings of several of the sessions at the symposium, and you can find them here.

The video sessions include:

"Why Is Eliminating P-Values So Hard? Reflections on Science and Statistics." (Steve Goodman)

"What Have We (Not) Learnt from Millions of Scientific Papers with P-Values?" (John Ioannidis)

"Understanding the Needs for Statistical Evidence of Decision-Makers in Medicine." (Madhu Mazumdar, Keren Osman, & Elizabeth Garrett-Mayer) 

"Statisticians: Sex Symbols, Liars, Both, or Neither?" (Christie Aschwanden, Laura Helmuth, & Aviva Hope Rutkin) 

"The Radical Prescription for Change." (Andrew Gelman, Marcia McNutt, & Xiao-Li Meng)

Closing Session: “Take the Mic”

The videos are stimulating and timely. I hope that you enjoy them.

© 2018, David E. Giles