Wednesday, August 15, 2012

BBC News - Olympic counties: Does it matter where medal-winners come from?

Wiggins Belgium and the South African cricketer
Andy Murray's gold postbox is in Dunblane, where the tennis gold medallist grew up - although he was, in fact, born in Glasgow, moved to Barcelona to train at 15 and now lives near Wimbledon in south-west London."

Saturday, August 04, 2012

Rajiv Sethi: Belief Heterogeneity

Rajiv Sethi: Belief Heterogeneity the paper described here analyses competing views.  This can be used in the model of speculation and the carry trade in particular.  The simple carry trade is successful for some time and the more successful it is, the more traders are drawn to the trade, increasing its success.  It requires a shock to burst the bubble.

"Not surprisingly, then, the presentation I found most appealing was that of Blake LeBaron. Blake is a pioneer in the development of agent-based computational models of financial markets, and the paper he presented belonged to this class. A large number of different forecasting strategies, some based on fundamental information and others on technical data analysis, compete with each other and with a traditional buy-and-hold strategy in his model. The resulting trading dynamics give rise to asset price returns that exhibit both moderate levels of short-run momentum as well as mean reversion over longer horizons. Moreover, the long run population of forecasting rules is ecologically diverse, with both passive and active strategies well represented. "

'via Blog this'

Crowds and networds

Tim Harford highlights the work of Mark Granovetter on networks and crowds.

: "Consider the following simple model of a potential riot, based on an idea published in 1978 by the sociologist Mark Granovetter. There are 1,000 people in a crowd of protesters, and all of them have some underlying tendency to embark on a looting spree. We might reckon that an outbreak of rioting might be triggered by insensitive policing, or by the poverty of the crowd, or the opportunities for theft or for violent protest. But for simplicity let’s assume that the only thing everyone in the crowd cares about is what everyone else in the crowd is doing. Some people will start looting without much company. Others will hang back until the riot is well under way."

This can also be used, I think, to look at the way that speculation can build.  Given the information cascade that builds when valuation is difficult and that activity of others can imply some understanding that may not exist.