Friday, October 19, 2012

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.


Rae F said...

It seems to me that having more children would be beneficial in an economy based on labor because your adult children could work with/for you and increase your profits.

N Lipscomb said...

The World Bank article hits the important issues of why richer countries produce smaller families more often. Obviously, family-planning provisions are a big factor (birth control and the like), though subject to controversy. Education and opportunity are probably right next to that: people simply find it rational to pursue various avenues of self-improvement before committing to raising a family. Obviously, there are a lot more factors, but I feel those are the two big ones. (WB has a few more.)

I was considering population ceilings in regards to economic growth: if marginal population increases per year are diminishing and we are potentially looking at some sort of horizontal asymptote just above a maximum world population level, we can still grow the economy through technological improvements (=> Supply), but will demand stay relatively fixed with a maxed-out population ceiling?
Recall shifts in aggregate demand such as: changes in expectations, changes in aggregate wealth, etc… (Factor out changes in the number of consumers as a possibility in respect to population remaining stagnant.)
What do you guys think?

Bri Heydlauf said...

In America, people work more now than they have in the past. Household incomes may be higher now, and does anyone think that people have smaller families because they are more focused on work and increasing their finances rather than being home, having children and raising a family? Perhaps it is priority oriented.

Bri Heydlauf

katy haran said...

I thought that it was interesting how the studies showed that poorer familes tended to not limit fertility. I would think that poorer parents would try to not have as many children because they would not have the funds to invest in them, but this study says otherwise. I would think that richer familes would have more children but I understand why richer familes limit fertility. They might want to have one or two children to invest in to make them the best that they can be and not worry about evolution because the family is already set for many years with the wealth that they have.

N Lipscomb said...

A lot of people from poor countries try to beat the odds of infant & child mortality by having more kids than we perceive as normal.
Also, the investment aspect of children is much different in some poorer nations. In some cases, the investment during infancy and childhood is shared by a community (usually an agrarian or similar close-knit community) and when the child comes of age, the benefits of an extra hand are shared by the community. This can lead to less of a perceived burden by individual families for having an extra child and more perceived benefits by the community (which would in turn encourage more population growth); I suppose I can compare this to an economies-of-scale effect within such communities. This type of occurrence is rare in rich countries where ideologies advocating individualism and privacy dominate the culture. Further, many household and job structures in the heavily-industrialized world are simply not able to take advantage of the aforementioned "economies of scale" effect.

Kendra C said...

Parents in richer countries tend to have higher education levels. While parents in poorer countries usually have little to no education. The level of education reached by an individual has been linked to the number of offspring they will produce. I agree with Rae F's comment. Large families in less developed nations would be beneficial, because there would be more hands to work. Parents in richer nations that reach education levels which allow them to obtain a reliable and good paying job do not need this extra incentive because they have a steady and reliable income that provides for their family.

A woman's education level has been shown to influence child births. Women with more of an education usually produce less children with high survival rates while women with little to no education tend to produce more children with low survival rates. High infant survival rates ensure that you genes will be passed on to the next generation. Less educated women tend to reside in poorer countries.

Cameron Visser said...

I would agree with a few points that posters already made. I would say that Education does have a lot to do with how many children you have. Also, the idea that in poorer countries it is almost like having a child is an investment that the parents make having to pay upfront to nuture the child while it is still young, however like a poster said earlier, as the child gets older it can work with?for the family and help boost family income. It seems like it almost comes down to a subconcious cost beneifit analysis. For a wealthy family the more children they have the the higher the cost (since with the addition of each child the more the inheritance is decreased), and if the family is wealthy to begin with it could be that the benefit (or income of the child does not make up for the cost). With a poorer family the inheritance is already low or non-existant so the cost is not high at all, where as the benefit from the child will be higher than the cost. However, I doubt that this is a concious decesion by most families, especially wealtier families.

Dr. Peter Schuhmann said...

Good stuff so far. To summarize, children can be an important source of labor & household income (Kendra and Cameron correctly suggest that this applies more in the developing world), access to family planning and/or birth control may differ by income and education, richer families may want to maximize the wealth endowment per child, and poorer nations may have economies of scale in child rearing.

Bri suggests that priorities may differ across nations. We can combine this idea with the higher education levels attained by women in richer nations, and apply the concept of opportunity cost to the family size decision. Anyone care to take a shot at it?

Mansfield F said...

Women who have higher potential earnings because they have a higher education level are more likely to work because the cost of having children is higher. This is due to changes in their opportunity costs. . Their opportunity cost will continue to increase as higher potential earnings increase. Higher potential earnings will incentivize more women to join the work force. Another part of opportunity cost that applies to women in the workforce is pay equality. By continuing to increase pay equality in the workforce and therefore increasing the opportunity cost of not working more women will be incentivized to work. This got me thinking about other factors that could affect the fertility rate. I think it is possible that there is some connection between social status aspirations and fertility rates. It would seem that they are inversely correlated because many times social status climbs are due to wealth accumulation and as the number of children increase less wealth can be dedicated to this wealth accumulation. I found a cool article on this topic.

Anonymous said...

It seems that children can be considered an investment. People with more money to spend can keep reinvesting in their children, and keep quantity down to a minimum. However, those with very little income need to invest in quantity, in the hopes of a higher chance of quality. However, no matter what, children have benefits and costs. In an article called “Help! Our Kids Are Driving Us Broke.” by Kate Ashford, extra expenses for one family included lessons’ for the kids, babysitting, braces, and non-child based expenses like savings plans and a hot tub (31). This article’s main purpose is to help parents with these extra expenses and to teach children about money management, but it also brings to light the kind of costs that are related to children. Now, these costs are within a higher income level household, but they are a great place to start looking at how income is spent within one family. A family unit with a higher income can think more about long-term benefits, and how their family structure can achieve those benefits. Those living in poverty do not have this luxury of waiting 30 years to see results from such an investment, and to reap the benefits. This thought process is very similar to what was discussed in class about a rich man and a five star dinner, compared to a poor man with a peanut butter and jelly sandwich. Also, perhaps those who were well educated and had higher incomes were over time better informed about over population and the consequences. It would have been interesting if the original “Small or Large Families” article addressed this issue.

Ashford, Kate. "Help! Our Kids Are Driving Us Broke." Money 37.1 (2008): 31-33.
Business Source Complete. Web. 3 Nov. 2012.

-Alice Wall