Forecasting Flowers

Last March I had a post that I titled "Modelling Flowers on the Wall". It was to do with the Great Victoria Flower Count that the people of this town engage early in each Spring in the hope of annoying friends and family living in less temperate parts of our continent.

In that post I developed an extremely sophisticated forecasting model that can be used to predict the flower count each year. The 2012 count is now on, so before the final numbers are in I'd better give you my forecast!

Here it is: 1,573,026,000 blooming flowers.

Oh, I almost forgot - the forecast standard error is 2,451,832,000. I think I'll be O.K.!

(You'll find the data and EViews workfile I used here.)

Postscript (9 March, 2012): The official tally was announced yesterday - 2,043,380,013.

© 2012, David E. Giles

You had to be there!

It was the Fall of 1983. I was on Study Leave from Monash University in Australia, and I was spending about 6 months in the Economics Department  at the University of Western Ontario. My good friend, Aman Ullah, had arranged the visit and I ha a wonderful time.

There were several seminar programs running on a weekly basis, including one in econometrics. Some time that term there was an econometrics seminar presented by two young Assistant Professors in the department. Here is how it went down.

Leap Year Econometrics

I guess there must be a few econometricians who were "leap year babies" - that is, born on 29 February. I'm not one of them, but a former co-author of mine was. This is the first February 29th since he passed away, and it's a good day to remember how much fun we had working together.

A Trick With Regression Residuals

Suppose that you've estimated an econometric model and you want to test the residuals for serial independence, or perhaps for homoskedasticity. The trouble is that for the model and estimator that you've used, your favourite computer package doesn't provide such tests. Is there a quick way of "tricking" the package into giving you the information that you want?

Computer Update

Now, this is really scary!!! (Even for nostalgia buffs.)

© 2012, David E. Giles

Tables or Graphs?

Should I present my results in a table or in a graph? Both have their place, of course.

A recent post, titled "Some Notes on Making Effective Tables", on the Cross Validated Community Blog, makes some interesting points and provides some good advice.

The CVCB is, by the way, an overflow blog for Cross Validated Stack Exchange, ".... a collaboratively edited question and answer site for statisticians, data analysts, data miners and data visualization experts."

© 2012, David E. Giles

Early Contributions to Training in Econometrics at the USDA

My colleague, Malcolm Rutherford, has recently published a really interesting paper on the history of statistical and economic education at the U.S. Department of Agriculture Graduate School. The school was founded in 1921, and exists to this day. As Malcolm explains, the USDA Graduate School played a seminal role in instruction in statistics in the 1930's, at a time when Econometrics was in its infancy.

The Neyman-Pearson Lemma: An Economic Perspective

In my graduate-level "Themes in Econometrics" course we've been talking recently about the Neyman-Pearson Lemma.  In 1933 Jerzy Neyman and Egon Pearson published one of the most important papers of modern statistics, referenced below. Specifically, they showed that we can use the likelihood ratio to construct the Most Powerful test (for a given significance level), when we are testing a point null hypothesis against a point alternative hypothesis. This set the scene for classical hypothesis testing as we practice it today.

ANZecmet

The following was circulated yesterday by Rob Hyndman, at Monash University:

"ANZecmet is a mailing list intended for econometricians in Australia and New Zealand, but may be of interest to a wider audience. It provides a forum for exchanging views, posting technical questions and responses, job advertisements, conference announcements, new publications, and so on.

The ANZecmet mailing list used to be hosted by Monash University, but is now in the process of moving to a Google group. If anyone on this list would like to join, please head over to

http://groups.google.com/group/anzecmet/about and sign up."

Econometrics has a long-standing and very strong presence in Australia and New Zealand. I've signed up, and I hope some of you will too.

© 2012, David E. Giles

"Asymptotic" Properties of Estimators and Tests

We're so familiar with "large-sample" asymptotics as a way of characterizing the behaviour of our estimators and tests in econometrics, that we tend to forget that there are other, very interesting ways of evaluating their behaviour, and approximating small-sample behaviour.

I touched on this in an earlier earlier post when I discussed "small-sigma" (or "small error") asymptotics. However, that's by no means the end of the story.