Tuesday, August 7, 2007

The Diversity Paradox?

An Article in the Boston Globe highlights Robert Putnam’s research on diversity. The take home message is that diversity seems to lower social capital, yet increase creativity and possibly economic growth. This is labeled a diversity paradox.

However, it seems to me that there is no paradox at all, at least with respect to creativity. Diversity increases creativity because it lowers social capital.

A sketch of a model:

There are two levels of social goods: global and local.

Finding a cure for cancer is a global social good; building a children's center is a local social good.

People are compensated for the production of social goods through status.

Each ethnicity has a different preference ordering over local social goods.

In a mulit-ethnic community there are fewer people who prefer any one social good. Therefore, the status return is lower to producing local socials goods. The status return to global social goods is constant everywhere.

When communities become more diverse people substitute the production of local social goods for global social goods.

That is, it is more difficult to become famous and loved by all for being a civic leader so I tend to invest more time in becoming famous and loved by all through some national level accomplishment.

This might suggest that diversity itself is a public good but I am not sure. That is, it could be that homogenous communities are piggy-backing off of the global social goods produced by diverse communities.

Hat-tip Mankiw

Monday, August 6, 2007

Losses II

Losses 0.9 Beta.

Something like this is probably going out.

Friday, August 3, 2007

What's Next

The start from what I am working on now

A Contribution to the Theory of IQ and Economic Growth

This paper takes Garett Jones seriously. Forty years after Robert Solow’s classic article suggested that long run growth depends on increases in total factor productivity Jones and Schneider (2006) proclaim:

stylized facts related to IQ and productivity are ready and waiting for the theorist who seeks to explain a large part of the puzzle of cross-country productivity differences. Accordingly, persistent difference in national average IQ—regardless of their source—may play an important role in answering Prescott’s (1998) call for a theory of total factor productivity

In a series of papers Jones, twice with Schneider argues, that

1) IQ is one of, if not the most powerful predictor of economic growth

2) IQ is a proxy for and indeed may be the primary source of otherwise unobserved worker heterogeneity

3) IQ correlates heavily with a tendency towards cooperation

4) The effect of IQ is more powerful at the macroeconomic level than the microeconomic level

5) The effect of IQ on growth rates is persistent and likely associated with higher growth rates rather than higher steady states

6) The importance of IQ on economic growth has been increasing since at least the mid twentieth century

7) At least in a naive sense the growth does not appear to cause changes in IQ

My goal below is to provide a theory consistent with these facts.

Nice work if you can get it . . .

The jobs report disappointed today at 92K vs. a consensus 130K. I believe this number is likely to be revised downward in the coming months because of the birth-death adjustment.

Each month the BLS has to estimate how many jobs were created in new companies and destroyed when old companies went out of business. The way it does this is by looking at how far its count was off a year ago.

That is, if last year the BLS counted 150K new jobs in July but then, after all new companies were firmly established, they went back and counted 170K new jobs they say that the birth-death adjustment needs to be 20K higher. In other words, last time they guessed 20K too few so this time they will add 20K to their baseline guess.

Here is the problem. Last time the housing market was surging and all sorts of upstart companies were coming on to cash in. Fly-by-night organizations that support builders, suppliers, etc.

Clearly those extra jobs aren't being created now and so the BLS is likely to be overly optimistic. By how much, I don't know. If there was a reliable way of fixing this problem then the BLS would use it. However, there is not and so we are left to readjust on our own.

Bottom line . . . job growth is slowing.

UPDATE: Commentors on Ritholz report that the Birth-Death adjustment for July is 26K new jobs. Typically, we find that around 50K are lost from companies' Birth/Death in July as kids get ready to go back to school, housing sales slow, etc. However, this time we got an estimated 26K created from Birth/Death. I strongly expect that to be revised downward.

Thursday, August 2, 2007

Fertility and the IQ of Nations

We have long known that economic growth was associated with decreasing family size. It appears the increases in IQ may also be associated with decreases in family size. The myriad of ways in which this trivariate correlation could be explained are tantalizing but for now I will leave you with the data itself.


I can't help but mentioned that if low IQ caused larger families then we would expect IQs to decline over time. In fact they have been doing the opposite. What I wouldn't give for good measures of Chinese IQ before the 1-child policy.