Thursday, November 29, 2012

Quote of the day

A sentence I've heard the other day:

'Getting published is like sex: when it is good, it is very good; and when it is bad, it is better than nothing’
(adapted from Dick Brandon)

It seems to be true: The curious correlation of quality and quantity in academic publishing.

Monday, November 26, 2012

The Richest Cities in the US in 1978 and Now

A study by McKinsey Global Institute showing the richest metros in the US in 1978 and now (via Jordan Weissmann).

[Click on the image to enlarge it]

Friday, November 23, 2012

A reply on 'Malthus and Potatoes'

In an earlier post I mentioned that Malthus didn't count on Potatoes. Actually, Prof. John R. Weeks (who writes an excellent blog, by the way), has pointed me an excerpt of Malthus' book where he acknowledges the role of potatoes on the population growth of Ireland during the 17th Century and the first half of the 18th Century (before the Irish Potato Famine). Thank you John!

The details of the population of Ireland are but little known. I shall only observe therefore, that the extended use of potatoes has allowed of a very rapid increase of it during the last century. But the cheapness of this nourishing root, and the small piece of ground which, under this kind of cultivation, will in average years produce the food for a family, joined to the ignorance and depressed state of the people, which have prompted them to follow their inclinations with no other prospect than an immediate bare subsistence, have encouraged marriage to such a degree, that the population is pushed much beyond the industry and present resources of the country; and the consequence naturally is, that the lower classes of people are in the most impoverished and miserable state. The checks to the population are of course chiefly of the positive kind, and arise from the diseases occasioned by squalid poverty, by damp and wretched cabins, by bad and insufficient clothing, and occasional want. To these positive checks have, of late years, been added the vice and misery of intestine commotion, of civil war, and of martial law. (Malthus, An Essay on the Principle of Population, II.X.38)

Thursday, November 22, 2012

Land use dynamics in the Brazilian Amazon

With the increasing importance of environmental issues on the international agenda, the Brazilian Amazon is receiving increasing attention from the scientific community. Although I am not particularly involved in environmental issues, I'd like to share with you some papers on land use dynamics in the Brazilian Amazon.

The first five papers of the list are authored by a few colleagues of mine from Ipea (Institute for Applied Economic Research, Brazil).

  1. Weinhold et al (2011) Soybeans, poverty, and inequality in the Brazilian Amazon

  2. Guedes et al (2011) Ecological Endowments, Poverty Dynamics, and Land Use among Smallholders in the Brazilian Amazon

  3. Barbieri and Guedes (2012) Demographic dynamics, livelihoods and land use change in the Brazilian Amazonia: a longitudinal study for the Machadinho Region, 1985 to 2010

  4. Sydenstricker-Neto (2012) Population and deforestation in the Brazilian Amazon: a mediating perspective and a mixed-method analysis

  5. Andersen et al (2002) The dynamics of deforestation and economic growth in the Brazilian Amazon

Related Link:

Monday, November 19, 2012

Thursday, November 15, 2012

Malthus didn't count on Potatoes

Here is one interesting paper that is mentioned at Banerjee and Duflo's book 'Poor Economics':

We exploit regional variation in suitability for cultivating potatoes, together with time variation arising from their introduction to the Old World from the Americas, to estimate the impact of potatoes on Old World population and urbanization. Our results show that the introduction of the potato was responsible for a significant portion of the increase in population and urbanization observed during the eighteenth and nineteenth centuries. According to our most conservative estimates, the introduction of the potato accounts for approximately one-quarter of the growth in Old World population and urbanization between 1700 and 1900. Additional evidence from within-country comparisons of city populations and adult heights also confirms the cross-country findings.

Another loophole in your Theory, Sr. Malthus....

Wednesday, November 14, 2012

Labor Shortages and Immigration Policy

Martin Ruhs and Lucie Cerna (both from COMPAS) give short talks on immigration policy, labor shortages and highly skilled migrant workers.

The subject of labor shortage in the engineering sector has been receiving an increasing attention in Brazil in the last decade. As we argue here, easing immigration rules to attract foreign engineers might be important to alleviate some local bottlenecks. However, it falls far short of what is needed to properly deal with this issue on a national scale.

If Brazilian authorities are considering taking concrete initiatives to deal with an eventual shortage of engineers in the country, then they should be aware of the following points before choosing any particular policy:

1.      There is a clear labor market matching problem: only three out of ten people with engineering degree actually work in a typical engineering occupation;

2.      Academic drop-out rates are remarkably high among engineering students (51% for women and 59% for men). Besides, addressing this issue is the only way to ensure short-term results;

3.      Possibly, the problem lies rather in education quality than in the quantity of students that the Brazilian education system is able to 'produce';

4.      Any rapid expansion in student intakes could compromise even further potential quality problems and yet, it would only yield results after six or seven years;

5.      Easing immigration rules to attract foreign engineers might play an important role to alleviate some local bottlenecks. However, it falls far short of what is needed to properly deal with this issue nationally;

6.      Finally, we draw attention that the claimed shortage of engineers in the country might not be a matter of purely quantitative supply, rather the spatial concentration of engineering schools and labor force play a rather important role in this debate.

Monday, November 12, 2012

Chart of the day: Chinese baby boomers

Poor Economics

I have just finished reading Poor Economics, a book by Abhijit V. Banerjee and Esther Duflo (both professors of Economics at MIT).* It brings into a sharp perspective the complex economic lives of the poor and the failure of some anti-poverty policies. It also brings up several creative studies, including some that have used randomized controlled trials. It's a really good reading! 

There is a website of the book where you can have a glimpse of it and explore interactive charts. Or, you may watch a short presentantion by Esther Duflo:

*Thank you Lucas Mation for the gift!

Thursday, November 8, 2012

Nate Silver's prediction the US election results

You' ve probably heard about Nate Silver by now - a young statistician that has been incredibly accurate at predicting baseball outcomes AND the 2008 and 2012 US presidential election results (More about this at Simply Statistics Blog).

He uses a bayesian approach to combine data from several polls and historical data to predict election outcomes. Nate Silver gave 'an interview' last month for Tim Harford where he explains shortly about bayesian statistics and his predictions for the US elections.

How good were his predictions?
[Image Source: Simply Statistics]

Soundtrack: I can't stop humming the bassline of this song.

Can mass transit really save the Environment?

Wednesday, November 7, 2012

A cellular automata intraurban model with prices and income-differentiated actors

Bernardo A. Furtado (a friend of mine from Ipea) have recently published this paper that I'd like to share with you:

A cellular automata intraurban model with prices and income-differentiated actors 
Environment and Planning B: Planning and Design 39(5) 897 – 924

This paper presents an intraurban cellular automata model that is an extension to White and Engelen’s pioneering model. The paper’s main contribution is to distinguish between agglomerative effects, determined by the attraction of the neighbourhood, and disagglomerative effects, driven by land prices, or land affordability. In order to do that, social heterogeneity is introduced in the model at the intraurban level. As a result, we can simulate both the evolution of land use and land prices. An application of the model and a sensitivity analysis indicate that neighborhood influence is the main driving force of cities’ spatial configurations. Prices, however, exert an important countereffect. Actually, the higher the influence of land prices, the faster land succession is observed. Finally, an important conclusion of the model is that intraurban models should not fail to differentiate actors by income level.

Evolution of actors in the Metropolitan Region of Belo Horizonte (Brazil), 1900-2000

[Image Credit: Furtado et al (2012) ]

Related Links:

Friday, November 2, 2012

Urban Picture

Beautiful (and somewaht scary) photos by Michael Wolf.
(via my great teacher Telmo Amand Ribeiro)

I really liked this one.

Enjoy you weekend!

Thursday, November 1, 2012

Message of the Day

obs. No, this is not the subtitle of this blog  although it could be