Worthwhile Canadian Initiative

Some basic facts about the distribution of sex

The Canadian Community Health Survey is an annual voluntary survey, carried out by Statistics Canada, that collects information about a wide range of health outcomes and risk factors. As part of the 2013-14 survey, 47,764  Canadians between the ages of 15 and 49 were asked about their sexual activity - whether or not they have ever had sex, and if they have had sex in the past year.

The majority of those surveyed reported being sexually active, as shown in the graph below. For example, about 88 percent of 18-19 year old women surveyed in 2013-14 (or 0.88) reported having sex in the last year.  For women, the probability of having had sex in the past year peaks at age 25-29. For men, it peaks 10 years later at ages 35-39. 

These estimates, because they are based on survey data, are subject to some margin of error. The vertical bars represent 95 percent confidence intervals - the true population mean will lie within that confidence interval 19 times out of 20. When there is little to no overlap between two confidence intervals, it is fairly certain that one group of people is having more sex than another group of people. So it is possible to say, with a high degree of confidence, that 18-19 year old girls are more likely to be sexually active than 18-19 year old boys, and 45-49 year old men are more likely to be sexually active than 45-49 year old women.

How can son preference persist?

In much of North Eastern India, there are 915 or fewer girls for every thousand boys - a sex ratio of more than 1.09 boys per girl. The persistence of such high sex ratios is puzzling, because it violates Fisher's Principle.

In most species, the ratio of males to females is approximately one to one. Fisher's principle explains why. In a society with fewer females than males, females achieve, on average, greater reproductive success than a typical male. Accordingly, any inheritable tendency that predisposes parents to producing females spreads. The number of females rises until, eventually, equality between males and females is restored.

So how can son preference persist?

The macroeconomics of Big Wedding cultures

How do you build a macroeconomic model of a "Big Wedding" culture? Do Big Wedding cultures spend too much on consumption and too little on saving and investment? If so, what's cause and what's effect?

I don't know the answer. I don't even really need to know the answer. But this question has been stuck in my mind for the past couple of days, so I'm writing this for self-therapy.

Questions always come from somewhere. Here's where this one came from.

For better or for worse - or for insurance coverage?

One of the puzzling things about the United States is its extraordinarily high marriage rate. Among OECD countries, only Turkey and Cyprus have a higher rate of marriage (Source, OECD).

Wife jokes as an indicator of marital discord

Last night I was watching a Best of Dave Allen DVD.  I like the funny wordplay, but some of the wife jokes are lame.

A wife joke is a joke like this one:

"First guy (proudly): "My wife's an angel!" Second guy: "You're lucky, mine's still alive."