Wednesday, April 16, 2014

The Age of Peak Academic Performance

An interesting paper on the age of peak academic performance (via Bernardo L Queiroz).

Great scientific output typically peaks in middle age. A classic literature has emphasized comparisons across fields in the age of peak performance. More recent work highlights large underlying variation in age and creativity patterns, where the average age of great scientific contributions has risen substantially since the early 20th Century and some scientists make pioneering contributions much earlier or later in their life-cycle than others. We review these literatures and show how the nexus between age and great scientific insight can inform the nature of creativity, the mechanisms of scientific progress, and the design of institutions that support scientists, while providing further insights about the implications of aging populations, education policies, and economic growth.
[click on the image to enlarge it]

Wednesday, April 9, 2014

Rise in Transport Costs in Brazil

In June 2013, the rise in Bus fares were the spark for huge protests in more than 80 cities in BrazilIn this report (published in Portuguese last year) we analyze some of the main pricing and funding issues of public transport in Brazil. The rise in transport costs in the country is just of them, and in which govermental policies have played an important role subsidizing gasoline consumption and the purchase of new cars.

For more details and a further discussion on this issue, you may read the report here.

And for now, here are some figures and a chart showing the increase in inflation and its transport components between 2000 and 2012 for the largest Brazilian metropolitan areas.

IPCA (Inflation): 125%
Bus fares: 192%
Gasoline: 122%
Owning a vehicle: 44%

[click on the image to enlarge it]

Label Translation:
  • IPCA = consumer price index
  • Tarifa de ônibus = Bus fare
  • Tarifa de Metro = Subway fare
  • Gasolia = Gasoline
  • Veículo próprio = Owning a vehicle (car or motocycle), including purchase and maintenance expenses.

Monday, April 7, 2014

200 years of Urban Expansion

We have mentioned the Atlas of Urban Expansion here at Urban Demographics a while ago. It is an amazing project supported by the Lincoln Institute of Land Policy that gathers loads of data for a number of cities across the globe.

Using part of these data, Shlomo Angel and the team at NYU Stern Urbanization Project have recently started working on a new series of great animations showing the expansion of 30 global cities over the last 200 years. Here are the first five cases: São Paulo, Chicago, Paris, London and Los Angeles:

obs. It's a great work and I'm looking forward for the next videos. The only reservation I would make is that these animations can be a bit deceiving as they give the impression of concentric urban expansion. 

Sunday, April 6, 2014

The motorcycle Kuznets curve

Nishitateno, S and Burke, P (2014) The motorcycle Kuznets curveJournal of Transport Geography. Volume 36, Pages 116–123.

The evolution of motorcycle ownership is a crucial issue for road safety, as motorcyclists are highly vulnerable road users. Analyzing a panel of 153 countries for the period 1963–2010, we document a motorcycle Kuznets curve which sees motorcycle dependence increase and then decrease as economies develop. Upswings in motorcycle ownership are particularly pronounced in densely populated countries. We also present macro-level evidence on the additional road fatalities associated with motorcycles. Our results indicate that many low-income countries face the prospect of an increasing number of motorcycle-related deaths over coming years unless adequate safety initiatives are implemented.

Fig. 4. Regression predictions for the motorcycle share of the motor vehicle fleet, for countries with mean and 90th-percentile log population density *.

(corresponding to 66 and 371 people per square kilometer, respectively). Prediction lines use a mean country fixed effect and the year-2010 time effect.

Saturday, April 5, 2014

Circular Migration Flow Plots in R

Guy Abel and Nikola Sander have recently published in the journal Science their paper on Quantifying Global International Migration Flows (ht MetroPop, by Ramon Bauer). 

Inspired by Martin Krzywinski's Circos and Mike Bostock’s D3.js library, they came up with this beautiful and interactive visualization of circular migration flow between 196 countries from 1990 through 2010.

You may download the data and find more information on the plot here. Abel also talks about the code he has used here and here to make similar charts in R (not interactive though). 

As I've mentioned in another post, it's not everyday you see demographers publishing on journals like Science and Nature. This paper will add to the massive presence of @IIASAVienna and @WiCVienna researchers in these two journals.

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