Editor's note: David Frum, a CNN contributor, is a contributing editor at Newsweek and The Daily Beast. He is the author of seven books, including a new novel, "Patriots," and was a special assistant to President George W. Bush from 2001 to 2002.
(CNN) -- When Richard Mourdock delivered his notorious answer about rape and abortion, I was sorry that the debate moderator failed to follow up with the next question:
"OK, Mr. Mourdock, you say your principles require a raped woman to carry the rapist's child to term. That's a heavy burden to impose on someone. What would you do for her in return? Would you pay her medical expenses? Compensate her for time lost to work? Would you pay for the child's upbringing? College education?
"If a woman has her credit card stolen, her maximum liability under federal law is $50. Yet on your theory, if she is raped, she must endure not only the trauma of assault, but also accept economic costs of potentially many thousands of dollars. Must that burden also fall on her alone? When we used to draft men into the Army, we gave them veterans' benefits afterward. If the state now intends to conscript women into involuntary childbearing, surely those women deserve at least an equally generous deal?"
That question sounds argumentative, and I suppose it is.
But there's a serious point here, and it extends well beyond the anguishing question of sexual assault.
If you're serious about reducing abortion, the most important issue is not which abortions to ban. The most important issue is how will you support women to have the babies they want.
As a general rule, societies that do the most to support mothers and child-bearing have the fewest abortions. Societies that do the least to support mothers and child-bearing have more abortions.
Germany, for example, operates perhaps the world's plushest welfare state. Working women receive 14 weeks of maternity leave, during which time they receive pay from the state. The state pays a child allowance to the parents of every German child for potentially as many as 25 years, depending on how long as the child remains in school. Women who leave the work force after giving birth receive a replacement wage from the state for up to 14 months.
Maybe not coincidentally, Germany has one of the lowest abortion rates, about one-third that of the United States. Yet German abortion laws are not especially restrictive. Abortion is legal during the first trimester of pregnancy and available if medically or psychologically necessary in the later trimesters.
Even here in the United States, where parental benefits are much less generous, abortion responds to economic conditions. In the prosperous 1990s, abortion rates declined rapidly. In the less prosperous '00s, abortion rates declined more slowly. When the economy plunged into crisis in 2008, abortion rates abruptly rose again.
These trends should not surprise anyone. Women choose abortion for one overwhelming reason: economic insecurity. The large majority of women who chose abortion in 2008, 57%, reported a disruptive event in their lives in the previous 12 months: most often, the loss of a job or home.
Of the women who choose abortion, 58% are in their 20s. Some 61% of them already have a child. Almost 70% of them are poor or near poor.
Three-quarters say they cannot afford another child.
Pro-life and pro-choice debaters delight in presenting each other with exquisitely extreme moral dilemmas: "Would you ban abortion even in case of rape?" "Would you permit abortion even when done only to select the sex of the child?"
These dorm-room hypotheticals do not have very much to do with the realities of abortion in the U.S. and elsewhere.
Here's an interesting example of those realities: The Netherlands has one of the the most liberal abortion laws in the world. Yet for a long time, the Netherlands also reported one of the world's lowest abortion rates. That low incidence abruptly began to rise in the mid-1990s. Between 1996 and 2003, the abortion rate in the Netherlands jumped by 31% over seven years.
What changed? The Guttmacher Institute, the leading source of data on reproductive health worldwide, cites "a growing demand for terminations from women in ethnic minority groups residing in the country." Well over half of all abortions performed on teenagers in the Netherlands are performed on girls of non-Dutch origins.
These girls and women weren't being raped. They weren't selecting for the sex of their child. They chose abortion because they had become sexually active within male-dominated immigrant subcultures in which access to birth control was restricted, in which female sexuality was tightly policed, in which girls who become pregnant outside marriage are disgraced and in which the costs and obligations of childbearing loaded almost entirely on women alone.
Abortion is a product of poverty and maternal distress.
A woman who enjoys the most emotional and financial security and who has chosen the timing of her pregnancy will not choose abortion, even when abortion laws are liberal. A woman who is dominated, who is poor and who fears bearing the child is likely to find an abortion, even where abortion is restricted, as it was across the United States before 1965.
So maybe at the next candidates' debate, a journalist will deflect the discussion away from "what if" and instead ask this:
"Rather than tell us what you'd like to ban, tell us please what you think government should do to support more happy and healthy childbearing, to reduce unwanted pregnancies and to alleviate the economic anxieties of mothers-to-be?"
Those are the questions that make the difference. It's amazing how little we talk about them.
The opinions expressed in this commentary are solely those of David Frum.