Interview with David Berri, author of _Stumbling on Wins_

Today features something a little different. Sports economist David Berri has a new book out, Stumbling on Wins. I was a big fan of Berri's first book, Wages of Wins, and regularly read his blog. I sent him a few short questions.

PVW: Whenever I read you write about your work, you seem to put it in terms of behavioral economics, but I've never actually heard you use the term. Do you identify yourself within that camp as an economist?

To answer your questions I am going to refer to the summary of behavioral economics offered by Alan Krueger at Princeton.

Krueger offers the following description of behavioral economics:

As Krueger notes, this is one of the fastest growing fields in economics. Stumbling on Wins is but one book drawing upon research from this field. For example, in Predictably Irrational, Dan Ariely presents evidence – drawn from laboratory experiments -- that human beings frequently fall short of the rational ideal. Nudge – by Richard Thaler and Cass Sunstein -- show how once we understand that people are not perfectly rational better policies can be designed. And How Markets Fail (by John Cassidy), The Myth of the Rational Market (by Justin Fox), and Animal Spirits (by George Akerlof and Robert Shiller), all demonstrate how behavioral economics can explain the causes of our recent economic downturn. So this is not just a field that is growing, it's also an important area of research.

PVW: It's been a few years since I read your excellent first book, Wages of Wins. As I remember it, the book was disproportionately weighted towards basketball, though it certainly had some chapters in other sports as well that would have been worth the price on their own. Does this book contain a similar percentage about basketball?

Stumbling on Wins covers research from baseball, hockey, basketball, and American football. The NBA is the primary focus of Chapter Two (Defending Isiah), Chapter Six (The Pareto Principle and Drafting Mistakes) and Chapter Eight (Is it the Teacher or the Students?). Hockey is the primary focus of Chapter Three (The Search for Useful Stats). American Football is the focus of Chapter Four (Football in Black and White), Chapter Five (Finding the Face of the Franchise), and parts of Chapter Seven (Inefficient on the Field). And baseball comes up in Chapter One (Maybe the Fans are Right) and parts of Chapter Six and Seven.

Essentially the book is trying to show that the Moneyball phenomenon (decision-makers in baseball were not valuing players correctly for much of baseball history) is something we see in all the major North American sports.

PVW: Did any parts of your new book surprise you when you first did the research?

Let me refer to what has become a classic cliché in answering your question. Specifically, it was Albert Einstein who said, "If we knew what it was we were doing, it would not be called research, would it?"

I think that quote captures the unpredictability of research. For each study we are asking some basic questions: What determines draft position of an NFL quarterback? What factors determine the pay of an NBA free agent? What factors determine wins in the NBA? How consistent are NHL goalies across time?

The answer to each question isn't known before we start investigating the issue. And the answers – given what we understand of the conventional wisdom – are all somewhat surprising.

PVW: What parts of the new book do you think will cause the most controversy?

This is hard to answer. The story that was picked up on first was the story on the impact a Final Four appearance has on an NBA's players draft position. I would not have guessed that story was going to be noted first and that demonstrates how hard it is to predict how people react to the stories you tell.

PVW: In 5 years, what overvaluations and undervaluations in the NBA do you think will persist?
This is one of the key questions addressed in behavioral economics. How quickly does new information get adopted by decision-makers? In traditional economics it is imagined that information is adopted instantaneously. In reality, though, the process seems much slower. We note in the book, baseball had the data to calculate on-base percentage since the 1860s. But it doesn't appear that it was correctly incorporated in the valuation of players until the 21st century. That record suggests that the overvaluation of scoring in the NBA might persist for some time to come.

PVW: If charges drawn was kept as an NBA stat, do you think it would improve the explanatory power of Wins Produced?

No, the explanatory power is based on the connection offensive and defensive efficiency has to wins. But it would allow us to connect part of what is currently counted for the team to the individual players. So our evaluation of players would be improved (although I doubt it would be much of an improvement).

Let me offer a few more details on Wins Produced:

The model used to measure player performance begins with the simple notion that wins in the NBA are determined by a team's offensive and defensive efficiency. From this statistical model we can derive the value – in terms of wins – of much that is in the NBA box score. These values tell us that wins in the NBA are primarily determined by shooting efficiency and the ability of a team to capture and maintain possession of the ball. This means that an NBA player helps his team win when he is an efficient scorer, grabs rebounds, captures steals, and avoids turnovers (i.e. the possession factors). Blocked shots, assists, personal fouls do matter. But shooting efficiency and the possession factors matter more.

The model explains 95% of team wins and is much more consistent across time than the plus-minus models. But it does tell us that players who score inefficiently, and/or who are below average with respect to the possession factors, do not help a team win very much. And this can be true even if the player scores more than 20 points per game. As a consequence, Wins Produced can produce results that contradict what people generally believe about NBA players. Again, popular perception is driven by scoring. So as we argue in the Stumbling on Wins, perhaps what we see from Wins Produced shouldn’t be that surprising.

PVW: Now, for a change of pace: which do you think will be easier to model: american football or football (soccer)?

I am currently doing more work on both sports. My sense is that soccer will be easier. But then again, research is often surprising. So I am not sure that will be my answer when my co-authors and I finish our research.

Thank you, Professor Berri.

Note: for the sports fan clicking through, this is a blog about Texas politics, so you'll probably be disappointed. The only post even remotely related is Rick Perry sponsoring Bobby Labonte. Although I'm not sure that the sabermetric statheads are NASCAR fans, perhaps they are.

Posted by Evan @ 04/08/10 12:09 AM


Previous Entry | Home | Next Entry


No comments yet

Add Comments

No flames or impolite behavior. HTML will be stripped. URLs will be transformed into hyperlinks.


Comments must be approved before being published.


+ Rick Perry vs World
+ About Me

+ Archives

+ Email:
  perryvsworld* at *gmail dot com


All content © Rick Perry vs. World and the respective authors.

Rick Perry vs. World is powered by Nucleus.

Site design and Nucleus customization by Kevin Whited.


+August 2017
+July 2017
+June 2017
+May 2017
+April 2017
+March 2017
+February 2017
+January 2017
+December 2016
+November 2016
+October 2016
+September 2016
+August 2016
+July 2016
+June 2016
+May 2016
+April 2016
+March 2016
+February 2016
+January 2016
+December 2015
+November 2015
+October 2015
+September 2015
+August 2015
+July 2015
+June 2015
+May 2015
+April 2015
+March 2015
+February 2015
+January 2015
+December 2014
+November 2014
+October 2014
+September 2014
+August 2014
+July 2014
+June 2014
+May 2014
+April 2014
+March 2014
+February 2014
+January 2014
+December 2013
+November 2013
+October 2013
+September 2013
+August 2013
+July 2013
+June 2013
+May 2013
+April 2013
+March 2013
+February 2013
+January 2013
+December 2012
+November 2012
+October 2012
+September 2012
+August 2012
+July 2012
+June 2012
+May 2012
+April 2012
+March 2012
+February 2012
+January 2012
+December 2011
+November 2011
+October 2011
+September 2011
+August 2011
+July 2011
+June 2011
+May 2011
+April 2011
+March 2011
+February 2011
+January 2011
+December 2010
+November 2010
+October 2010
+September 2010
+August 2010
+July 2010
+June 2010
+May 2010
+April 2010
+March 2010
+February 2010
+January 2010
+December 2009
+November 2009
+October 2009
+September 2009
+August 2009
+July 2009
+June 2009
+May 2009
+April 2009
+March 2009
+February 2009
+January 2009
+December 2008
+November 2008
+October 2008
+September 2008
+August 2008
+July 2008
+June 2008
+May 2008
+April 2008
+March 2008
+February 2008
+January 2008
+December 2007
+November 2007
+October 2007
+September 2007
+August 2007
+July 2007
+June 2007
+May 2007
+April 2007
+March 2007
+February 2007
+January 2007
+December 2006
+November 2006
+October 2006
+September 2006
+August 2006
+July 2006
+June 2006
+May 2006
+April 2006
+March 2006
+February 2006
+January 2006
+December 2005
+November 2005
+October 2005
+September 2005
+August 2005
+July 2005
+June 2005
+May 2005
+April 2005
+March 2005
+February 2005
+January 2005
+December 2004
+Acton MBA
+Ethereum News
+ICO Calendar
+How to prepare for CFA exams