Gutti, Gutti Macher, Whither Do Ye Wander?
Regarding the recent post on statistical illiteracy among people citing the Guttmacher Institute report on contraceptive use, a few clarifications are in order.
- The issue is not whether contraceptive use is a Good Thing, especially for Those People, that pregnancy is a disease, or that a baby is a tumor or parasite. Female contraceptive use is certainly a good thing for guys, since it makes women sexually available without an implied responsibility for child-raising.
- The issue is not whether lots of Catholic women use contraceptives. Catholic doctrine is (mirabile dictu!) not predicated on current social popularity. At one time, that would have meant approving of gladiatorial games. After all, nearly everyone has at one time in their lives pilfered office supplies from their place of employment; yet, no one supposes either that the government should pay for burglary tools for kleptomaniacs ("property-challenged") or that the Church should be forced to pay for them despite teaching that stealing is wrong.
- The issue IS whether the executive branch has the authority to issue decrees forcing anyone, let alone religious institutions, to pay for contraceptives. If it is true that 98% use contraceptives -- and it isn't, really -- then they cannot really be hard to acquire. One wonders how women got them for all these years since Griswold.
Now, the NSFG applied only to women of childbearing age, taken as (15-44), and the percentages need to be understood as percentages of this cohort. That lets a lot of nuns off the hook. Let's take a look at the key Table 4 on page 21 of the report. If the captured screen shot is illegible, the table can be found here: http://www.cdc.gov/nchs/data/series/sr_23/sr23_029.pdf
Why % Means Nothing Unless You Know NEasily said. What Guttmacher did was take the percentages for contraceptive use and apply them only to the 62% who used contraceptives! Thus, if 17.3% (of all women in child-bearing years) reported using the Pill, that became 17.3/61.8 = 28% (of all contraception users), and so on.
It is also important to note that this means women who have used contraception at least once. In table 15, we learn that something on the order of 30% of such women discontinued use for one reason or another. Biggest reason for discontinuing the Pill was experiencing side effects. For condoms, the biggest reason was that the boyfriend didn't like using one. About 2% said their insurance did not cover it; and 3% said it was too expensive. (These are percentages of Pill-users.) Interestingly, about 10% of Pill-users stopped using the Pill because they got pregnant.I found nothing in the NSFG relating to religion, so I cannot say how Guttmacher was able to reconstruct those particular percentiles. Due to differences in methodologies, it is always tricky to combine the results of more than one study.
Since Darwin came up somehow in the previous post, I thought I would ask Chuck what he thought of contraception:
Hence our natural rate of increase, though leading to many and obvious evils, must not be greatly diminished by any means. There should be open competition for all men; and the most able should not be prevented by laws or customs from succeeding best and rearing the largest number of offspring. (emph. added)
-- Charles Darwin, The Descent of Man, and Selection in Relation to Sex (2nd ed., 1882) pp. 618.