Ein Beispiel einer Vorlesungsstunde für potentielle angehende Studierende. Es geht um rationales Herdenverhalten. Wenn ein Produkt von vielen Menschen gekauft wird, heißt das dann, dass es ein gutes Produkt ist? Warum gehen wir lieber in das volle Lokal? Und was bedeutet das für andere?
This post builds on the previous two, economics on the beach II and economics on the beach III. I have started this, so I need to finish this now. In this post I will finally try to build a small model in which it is true that “charging a perhaps even substantial price for beach access would be welfare improving for all potential beach goers”.
I will try and build a small model in which it is true that “charging a perhaps even substantial price for beach access would be welfare improving for all potential beach goers”, a claim I made in my last post. In this post I will take a first few steps in this direction, first only demonstrating my claim that beaches potentially suffer from the “tragedy of the commons” before I will tackle the main question in the next post.
There are things you want to do only with lots of other people. Go see a football game, for instance, or a pop concert. You would feel rather silly being the only one clapping and cheering. You might also prefer not to be the only couple in a restaurant. Aside from the growing feeling that you are probably in the wrong place, you miss the background chatter, the gentle clashing of dishes, the constant moving around of busy waiters. You would miss atmosphere.
But the beach, for me at least, could do with fewer people.
It could easily have ended in a fist fight. Or more likely a plastic shovel fight. This is how it began. My kids, my wife, and I went down to a Cornish beach. A beach with an interesting feature. There is a small stream that runs high up the beach parallel to the sea for more or less the whole length of the beach. Kids find this stream almost more fun to play in than the often pretty rough sea, which is mostly inhabited by bodyboarders smashing into each other. As the stream runs essentially over and through sand with lots of stones around as well, it is very malleable. Kids (and, invariably, their fathers – mothers do not seem so keen) love to build little dams, dig up new channels, and create little pools to play in. On the given day, easily 20 to 30 kids (and some of their fathers) were happily engaged this way somewhere along the length of the stream, when suddenly the water was reduced to a tiny trickle and had stopped flowing altogether further down the stream.
One of my colleagues sent me an article in the Financial Times from March 17 entitled “How to save a penalty: the truth about football’s toughest shot. On star goalie Diego Alves, game theory and the science of the spot kick.” I found the article interesting for two reasons.
- It has a fun discussion of the psychology and game theory of taking penalty kicks. It points to the paper by Ignacio Palacios-Huerta in which he shows that professional soccer players take penalties in a way that is consistent with Nash equilibrium (or minmax) behavior. The FT article also includes an interesting interview with Ignacio Palacios-Huerta and his “analysis of ideal penalty-taking strategies for the then Chelsea manager Avram Grant before the Champions League final against Manchester United in 2008.”
- The FT article highlights Diego Alves, Valencia’s goalkeeper, and argues that he is particularly good at stopping penalties. The FT article argues that Diego Alves’ stopping record (he stopped 22 of 46 penalties – a very high number compared to the average stopping rate of 25% of all goalkeepers combined) cannot be explained by chance alone.
In this blog post I want to comment on the 2nd point. It is actually wrong. And it is wrong for an interesting reason. Moreover the mistake made is very easy to make and is a very common one.
The Wachau is a roughly 40km long and narrow part of the Danube valley in Austria. It produces and sells essentially only three things: beauty, wine, and apricots. With “producing and selling beauty” I mean that it tries to and manages to attract tourists. Its wine-growing and trading goes back a long way.
Except for perhaps in pre-historic times, it seems that the Wachau was never autarkic, meaning there was always trade (and probably also migration) between the Wachau and the world around it.
Now suppose, counter-factually, that the Wachau were and had always been completely cut-off from the world. What would the Wachau be like?