Dollars and Sex (27 page)

Troy's aunt's reaction when he was asked about taking the necessary classes for entrance to college is a good example of how culture plays a role in teenage sexual behavior. Troy's family has been economically marginalized for several generations, while over the same period the affluent families in their community have come to hold the majority of wealth. His family's inability to change their fortunes in the past created a culture of despair within the family.

Troy's family believed that he would never rise above their current standard of living and, as a result, never expected him or his cousin to finish high school. While ultimately it was economic hardship that prevented Troy from finishing high school, the fact that no one ever told him that he was capable of furthering his education played a role in that decision. Troy's cousin, on the other hand, finished high school but went no further; instead, he found work to support his girlfriend and their baby. Their choices may not have guaranteed that they stay within their low socioeconomic class, but they did make it significantly more difficult to improve their living standard than it would have been had they not had a baby in high school.

POSTSECONDARY EDUCATION IS A PRIVILEGE

The reality for many students is that they don't need a culture of despair to discourage them from believing that they will go to college. If college were affordable for everyone, then even teens from underprivileged families could dream of one day having a high-paying job that requires a college degree. As education is costly, however, the reality faced by many students is that they will never be able to afford to go to college. If this is the case, then having a baby in high school does not limit their options in terms of furthering their education—because more education never was a viable option.

That suggests that there might be a relationship between teen pregnancy and the price of a college education.

A recent paper by economist Benjamin Cowan uses nationally representative U.S. data to determine if teens in states with lower tuition and fees for public community colleges make better sexual choices in response
to increased optimism about future education. He finds that a $1,000 reduction in price of a community college education decreases the number of sexual partners the average 17-year-old high school student has by a remarkable 26 percent.

He also finds that students are less likely to engage in other risky behaviors, such as smoking (down by 14 percent) and marijuana use (down by 23 percent), when college is affordable.

Of course, this argument assumes that teenagers are rational, forward-looking individuals who understand that risky sexual behavior today has the potential to impose costs on them in the future. The idea that teens are rational when it comes to sexual decision making may be a tough sell, but this paper finds that for students in their final year of high school, an increase in college tuition by $1,000 reduces a student's expectations of continuing in school by 5.7 percent, implying that teens do take the cost of education into consideration when setting their expectations about their future.

He also finds that far fewer students continue their education after high school than those who think they will: 83 percent of high school seniors believe they will be enrolled in school in one year's time while only 56 percent actually find themselves in a university or community college. Those, perhaps false, expectations explain why we observe such a big change in teen sexual behavior despite the evidence that not all students continue in school—they don't need to continue; they just need to believe that it is possible.

I said earlier that the teen pregnancy rate in the United States is the highest in the developed world and more than double that of its closest neighbor (thirty-nine births per thousand teenage woman in the United States, compared with fourteen births per thousand teenage women in Canada). This disparity in teen pregnancy rates is even greater when we compare the United States to European nations that provide very inexpensive postsecondary training. The teen pregnancy rate in the United States is three times higher than in Germany and France and four times higher than in the Netherlands. The most obvious, economic,
explanation for the differences in teen pregnancy rates between the United States and other developed nations is that teenagers from low-income families in the United States have more reason to be pessimistic about their postsecondary educational opportunities than do similar teenagers in other countries.

LESS SEX IS MORE SEXUALLY TRANSMITTED DISEASES

Promiscuity in U.S. high schools, as I have already said, is at a twenty-year low and teen birth rates have fallen by over one-third from 1991 to 2009. How can it be that teens are sexually active at lower frequencies, and appear to be taking more precautions, and yet 50 percent of new STD infections last year were in people younger than 24?

To understand the answer to this question, imagine a school where there are one hundred students, of which fifty are sexually active with other students in the school. It doesn't matter what their gender is, nor does it matter if they are heterosexual or not; what matters is that they are not in monogamous pairs: they are teenagers after all and so each one can have several sexual partners over the course of a year.

At the beginning of the year, one student arrives infected with an STD. Given that students are not in committed relationships, that student infects his/her partner, who then infects his/her next partner, and so on. By the end of the year, a certain percentage of students in the school are infected—presumably less than half since only 50 percent are sexually active.

Now imagine that the following year, another hundred students arrive at the school, but now only forty students are sexually active. Again, at the beginning of the year, one student arrives with an infection and the whole process starts all over again. Now given that there are fewer sexually active students, we might be tempted to predict that fewer students are infected by the end of the year. But, that prediction would probably be wrong.

Not all students behave in the same way when they are sexually active, and chances are that the students who have chosen to not have sex in this
year are the students who, had they been sexually active, would have taken the greatest precautions to prevent infection; they are the students who are the most
risk averse
.

For example, consider the behavior of the following three people. The first person is very risk averse and always insists on proper condom usage. The second person is risk neutral and neither insists nor refuses condom usage. The third person is risk loving and always insists on sex without a condom.

In the past, when more teens were sexually active, the risk-averse person might have ended up in a sexual relationship with the risk-neutral person. If that was the case, then both would be protected from sexually transmitted disease (the risk-averse person would insist on condom usage and the risk-neutral person would comply with that request).

When the costs of sex increased, for example, because college education became more important to future income, teens like the risk-averse person stopped having sex altogether. Now a greater proportion of those having sex on the high school market are just like the second (risk-neutral) and third (risk-loving) people.

The risk-neutral person, who might have been protected in the past from infection by a diligent risk-averse partner, is now having sex with a risk-loving partner. The risk-loving partner insists that no condom is used and the risk-neutral person complies with that request, so both are at a much greater risk of infection.

When the most risk-averse students are removed from the teen sex market, then not only will the infection rate not decrease, but it could very well increase. This is because sexually active teens who might have otherwise found themselves with cautious sex partners are left with partners who are more risk neutral—or even risk loving—when it comes to safe sex.

Economists call this a change on the
extensive margin
—otherwise safe sexual partners have left the market leaving the remaining sexually active teens at greater risk of infection. There is a second change that can explain
the rising rates of STDs and that is a change on the
intensive margin
—those people still on the teen sex market have changed their behavior in a way that has increased risk.

A recent paper by economists Peter Arcidiacono, Andrew Beauchamp, and Marjorie McElroy finds that in schools in which teenage women outnumber teenage men, the gender imbalance increases the willingness of women to participate in relationships that involve sex. (This is very similar to the story told earlier that said that in college, girls are more sexually active than they want to be when male college students hold all the “market power.”)

They find, for example, that when grade-twelve men outnumber grade-twelve women, the fraction of grade-twelve girls who are in a relationship and having sex is much higher than the fraction who stated that they want to be in a relationship that involves sexual intercourse. They also find that the fraction of grade-twelve boys who are in a relationship and having sex is very similar to the fraction that stated that this is their preference; they want to be in a relationship that involved sexual intercourse.

This says that, in grade twelve, boys have greater bargaining power over sexual activity because they are having as much sex as they want, and the girls have less bargaining power over sexual activity because they are having more sex than they want.

Just as on the college market, this relationship exists because grade-twelve girls have to compete for scarce grade-twelve boys, not only because boys are less likely to finish high school but also because grade-twelve girls have to compete with girls in younger grades who are happy to have relationships with older boys. This market power of older boys not only puts pressure on girls to have relationships that involve sex (even when they would prefer that they didn't), but it also hands bargaining power over to boys when it come to the decision to consistently apply protection against disease (i.e., wearing a condom).

Since women face higher risks of infection from unprotected sex than do men, giving men bargaining power over condom use leads to lower rates
of condom usage because those making the decision face a lower cost of unprotected sex and, it could be argued, have a greater benefit from not using a condom.

Add to this the fact that older boys are not only transmitting infections to girls in their own year but also to girls in the cohort below them, and you have the making of an epidemic as diseases are passed through the “generations” of students.

This brings us to the issue of race that I raised earlier in the chapter, particularly the observation that girls who are black have significantly higher rates of STDs than girls who are either white or Hispanic. The authors of this paper observe a strong same-race preference in matching among high school students; specifically they find that over 86 percent of the couples in their sample are ones in which both people are of the same race. Black women were significantly more likely to be in a match with a black man than a man of any other race; 99 percent of black women were having sex with black men. Also, they find that the black teenage men in their sample are more likely to be having a relationship with someone of a different race than are black teenage women; 11 percent of black men were matched with women of a different race.

When we consider the observation that the recent high school completion rates for black men are between 7 and 12 percentage points lower than for black women (according to James Heckman and Paul LaFontaine), all the evidence suggests that black teenage women are competing with each other and with women of other races for far fewer black men on the high school market.

The evidence from the Arcidiacono paper I discussed earlier implies that this gender imbalance will result in black women having sex at much higher rates than would be their preference had there been a more even playing field. It also suggests that the bargaining power handed to black men as a result of their market power will lead to much higher rates of unprotected sex.