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.
Of course sexually active married people may not be having sex with their husband or wife - indeed the slight divergence in the married sex lines when people reach their 40s is suggestive of an uptick in male extra-marital sexual activity. There may also be selection effects at play, that is, people with strong sex drives may be more likely to get and stay married.
The above diagrams distinguish between the celibate and the sexually active but do not, for people who are sexually active, capture the frequency of sexual activity. One way of getting at sexual frequency is with information about the form of birth control used. People in long-term relationships will typically invest in easy to use, reliable and non-intrusive forms of contraception, such as the birth control pill or the Minera IUD. For a short-term relationship or a one night stand, however, a condom is a wise choice. Condom use, therefore, can be taken to be an indicator of irregular sexual activity. This next diagram presents the portion of people who used a condom in their last sexual encounter:
Men are consistently more likely to report using a condom the last time they had sex than women are. Some of this difference, however, is likely due to the fact that gay men often use condoms during sex, but lesbians do not.
For young adults, the CCHS also collected information on the use of condoms for birth control purposes - numbers which should not be affected by differences in condom use between gay men and lesbians. Again, the same pattern of greater male condom use appeared:
This graph is consistent with the idea that women in their early twenties are not only more likely than their male contemporaries to be sexually active, they are also more likely to having sex in the context of a long-term relationship, where there are regular opportunities for sex.
Recent discussions about the "incel" - the involuntarily celibate - have raised questions about inequality of sexual experience. These charts raise two points relevant to this debate.
First, there is a difference between inequality of sexual opportunity at a point in time, and inequality of sexual opportunity from a life-time perspective. A number of men who are not having sex at 18, 20 or 22 may well be more sexually active by the time they hit their late 30s, and the reverse will be true of their female contemporaries.
Second, the greatest facilitator of sex is marriage and cohabitation. Anyone who is concerned about reducing inequality in access to sex should actively work to create the conditions that allow people to marry, or enter common-law relationships.
There is a large literature suggesting that people are more likely to get married if they have steady employment, and earn enough to buy a home with space to raise a family in. This means that there is no conflict between fighting for greater economic equality and fighting for greater sex equality. The policies that reduce income and wealth inequality are the same policies that put money in people's pockets so they can afford to go on a date. They're the policies that help people afford their own homes, where they can get down and dirty any time they want (at least until kids come along).