Tag: LiteratureReview

08
Nov

Coarse PM and measurement error paper

Howard Chang, a former PhD student of mine now at Emory, just published a paper on a measurement error model for estimating the health effects of coarse particulate matter (PM). This is a cool paper that deals with the problem that coarse PM tends to be very spatially heterogeneous. Coarse PM is a bit of a hot topic now because there is currently no national ambient air quality standard for coarse PM specifically. There is a standard for fine PM, but compared to fine PM,  the scientific evidence for health effects of coarse PM is relatively less developed. 

When you want to assign a coarse PM exposure level to people in a county (assuming you don’t have personal monitoring) there is a fair amount of uncertainty about the assignment because of the spatial variability. This is in contrast to pollutants like fine PM or ozone which tend to be more spatially smooth. Standard approaches essentially ignore the uncertainty which may lead to some bias in estimates of the health effects.

Howard developed a measurement error model that uses observations from multiple monitors to estimate the spatial variability and correct for it in time series regression models estimating the health effects of coarse PM. Another nice thing about his approach is that it avoids any complex spatial-temporal modeling to do the correction.

Related Posts: Jeff on “Cool papers” and “Dissecting the genomics of trauma

24
Oct

Archetypal Athletes

Here is a cool paper on the ArXiv about archetypal athletes. The basic idea is to look at a large number of variables for each player and identify multivariate outliers or extremes. These outliers are the archetypes talked about in the title. 

According to his analysis the author claims the best players (for different reasons, i.e. different archetypes) in the NBA in 2009/2010 were:  Taj Gibson, Anthony Morrow, and Kevin Durant. The best soccer players were Wayne Rooney, Leonel Messi, and Christiano Ronaldo.

Thanks to Andrew Jaffe for pointing out the article. 

Related Posts: Jeff on “Innovation and Overconfidence”, Rafa on “Once in a lifetime collapse

15
Sep

When overconfidence is good

A paper came out in the latest issue of Nature called the “Evolution of Confidence”. The authors describe a simple model where two participants are competing for a resource. They can either both claim the resource, only one can claim the resource, or neither can. If the ratio of the value of the resource over the cost of competition is good enough, then it makes sense to be overconfident about your abilities to obtain it. 

The amazing thing about this paper is that it explains a really old idea “why are people overconfident” with really simple models and simulations (done in R!). Based on my own experience, I feel like they may be on to something. You can’t get a paper in Nature if you don’t send it there…