Family size and wealth

Nikolai's response regarding Hardin and population growth got me thinking about this... 

Here is an interesting read at ENN regarding family size, household wealth and evolution. 

The research appears to be seeking an evolutionary explanation for slowing rates of population growth. We know that world population growth is slowing. i.e. population is growing, but not nearly as fast as it has in the past. The UN has predicted that world population will plateau by around 2050, at a population somewhere between 7.4 and 10.6 billion people (best guess is 8.9 B). This is despite significant increases in longevity and lower mortality rates due to advances in medicine and sanitation.  The slowing of population growth is due to lower birth rates. People are deciding to have fewer children, mostly in  developed countries.


The article summarizes the results of a study which attempted to test the hypothesis that having fewer children leads to future reproductive success for offspring due to the advantages of wealth. i.e. having fewer children conveys an evolutionary advantage, if having fewer, but richer children today increases the likelihood that your genes will multiply in the future. 

I'm not sure I follow this line of reasoning, but in any event, the authors of the study did not find support for the hypothesis. However, there are a lot of economic reasons why parents in richer nations might have smaller families than parents in poorer nations. Can anyone think of these?

Here is more reading at the World Bank.

Here is a long report from the UN on population growth and predictions for the future.

One step closer to a global carbon market

Australia joins the EU carbon trading program.
Read about it here at Triple Pundit.

Collaboration and the commons

I've been working on a chapter describing the Tragedy of the Commons for the forthcoming Encyclopedia of Natural Resource Economics (I'm also writing one on Coastal Resource Economics, more about that one soon).  Hardin discusses the tragedy of depletion as an inevitable result when natural resources are rival and non-excludable, noting that self-interested users will tend to ignore the social costs and focus on maximizing personal benefits. To solve the problem, Hardin called for privatization of the commons or government control via rationing or taxation.  We see many modern day examples of this tragedy, from over-fishing to atmospheric pollution. As I've noted on more than one occasion, all of us can be seen as the herdsmen of our day in one way or another.  

It's important to point out that Hardin's tragedy does not always unfold as he described. Under certain conditions, collective action (group management) can be an effective means of achieving environmentally sustainable and economically efficient outcomes for common pool resources. Elinor Ostrom (winner of the 2009 Nobel Prize in Economics) was a leading researcher in this area.

Here is an excellent summary of Ostrom's work.

Read more about Ostrom's work here and here.

A similar notion is provided by this interesting new sharing site. 

Lots of reading on the Tragedy here at Science.