Monday, April 29, 2013

Moving to R

I have finished my third week of introductory classes on R using RStudio and I must say I'm a converted. I know R can be disproportionately complicated to do a few simple things (such as pie charts or box plot) and I noticed how it can be discouraging because of that. However, it can also turn complicated ideas into just a few simple code lines (a good example). It's extreamily flexible. So I've decided I'm gradually moving to R. I know it will take some time, but it will eventually be completed.

As a consequence, from now on we'll have more R-related posts convering useful tips for urban and demographic studies.

note. I was first introduced to SPSS during my Sociology undergrad. And even though I have had SAS classes and a little contact with STATA, I got stuck with SPSS. I know I shouldn't be saying this out loud. But I'm ready to move on now.

Related Links:

Saturday, April 27, 2013

Disabled Population in Mexico City

Miniature Melbourne

Why do I like tilt-shift time-lapse videos so much? I think it's because these kinds of shots give us a sensation that we could get the big picture of how things work  when of course we can't 

Friday, April 26, 2013

Latin American Human Mortality Database

Some of you have probably heard about the Human Mortality Database. Now, Prof. B. Piedad Urdinola (National University of Colombia) and Prof. Bernardo Lanza Queiroz (Cedeplar/UFMG, Brazil) have recently started a new project with a similar idea but covering Latin American countries. It's the Latin American Human Mortality Database.

It brings tons of information and it's really well organized with easy navigation.

"At present the database contains detailed information on mortality for five countries in Latin America: Argentina, Brazil, Colombia, Mexico and Peru. All information is broken down by age, sex, region and cause of death. Additionally there is information on the academic literature on the study of mortality for these same countries."

Long live the project!

Thursday, April 25, 2013

Urban Picture

Brooklyn Bridge (1914)

[Image Credit: Eugene de Salignac via Daily Mail]

Monday, April 22, 2013

An experimental confirmation of the Spatial Mismatch Hypothesis

Self-recommending: Getting to Work: Experimental Evidence on Job Search and Transportation Costs, by David Phillips.

In urban areas job vacancies often exist but poor, minority residents tend to be concentrated in neighborhoods with limited geographic access to these jobs. Using a randomized field experiment with public transit subsidies, I test whether this spatial mismatch of workers from jobs causes poor labor market outcomes. Randomly selected clients of a non-profit employment agency received a public transit subsidy to assist in applying to jobs and attending interviews with potential employers. I find evidence that the transit subsidies have a large, short-run effect in reducing unemployment durations with treatment causing the probability of finding employment within 40 days to increase by 9 percentage points, from 0.26 to 0.35. After 90 days, this difference narrows to a large but statistically insignificant 5 percentage points. I find weaker evidence that this decrease in unemployment duration results from more intense search behavior, with the transit subsidy group applying to more jobs and jobs further from home. To my knowledge, these results provide the first experimental confirmation that spatial mismatch of workers from jobs can cause adverse labor market outcomes for poor, urban individuals.
This study was presented last year at a conference on 'Research on Urban Mass Housing' that took place at Oxford. Nice programme, by the way.

Chart of the Day

obs.1 It's hard to believe Rio de Janeiro would be more polluted than Sao Paulo. I would love to hear a specialist analyze this.

obs2. You may explorer the data here, or navigate a map by clicking here.

[Image Credit: The Economist]

Tuesday, April 16, 2013

Replay: UN Demographic Manuals On-line

Here is the link for the classical manuals and guides of demographic methods and techniques issued by the United Nations a long time ago. It presents a series of 23 manuals organized by the Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat.

Friday, April 12, 2013

Paper for the weekend

Here is a paper I would like to have time to read. The abstract is great.

Ball, J. A. (1973). The zoo hypothesis. Icarus. Volume 19, Issue 3, Pages 347–349.

Extraterrestrial intelligent life may be almost ubiquitous. The apparent failure of such life to interact with us may be understood in terms of the hypothesis that they have set us aside as part of a wilderness area or zoo.

The is just one of the 11 Weirdest Solutions to the Fermi Paradox (ht @phgfsouza). There can't be a better solution than #4 !


Thursday, April 11, 2013

Forecasting Migration

Andres Marroquin points to this chart showing long-term trends of net migration by continent. [By the way, the original report has many interesting charts that give a clear summary of global demographic trends]

When we hear the words “long-term migration” in the same sentence, it is impossible not to remember one prominent Achilles' heel in demographic studies: the inability to forecast long-term migration. Here is Willekens' opinion on this topic.

Why is it not possible to do long-term [migration] forecasts?
The data from statistical offices are not suitable for long-term migration forecasts. The reason is that these data document the outcome of migration flows – not the reasons behind them. Predictions on the basis of past behaviour are reliable when the system is stable, i.e. when conditions do not change and people respond to these conditions in the same way as people in the past. But conditions change, for instance when regulatory measures are taken to prevent migration flows, or events occur, like political changes in the country or natural disasters. (Frans Willekens)

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Monday, April 8, 2013

The Future Cities Agenda, by M. Batty

Michael Batty's agenda for future cities (pdf).
The key issues on the agenda involve: automating cities which is an inevitable consequence of networking and the decentralisation of all aspects of computation across the globe; the dominance of migration as a force for local change; globalisation where everyone who uses the net is in some way part of a world city of sorts (with the implication that every city, no matter what size, has elements of ‘world city’ within it); the consequences of aging which will change the way we physically move around the city combined with the automation of transit and the private automobile; the rise of health care as a basic urban function; the demise of physical retailing and the ‘high street’, as much through online activity as through physical decentralisation; and, of course, the general automation of all sectors of the economy. Many problems confound this agenda and it is worth noting these as they are likely to dominate the extent to which we are able to build resilient and sustainable cities that are smart enough to enable them to function better than any of those we have created in the past.

Friday, April 5, 2013

Quote of the Day

"The scientist is not a person who gives the right answers, he’s one who asks the right questions."

....and that's one of the hardest parts of doing science.

Thursday, April 4, 2013