||the conflict between concerns over world population growth and respect for reproductive rights. It is a remarkably simple question: What if everybody did it?â€"that is, what if everybody used "automatic," background contraception? The Effects of Universal Background Contraceptive Use. What if everybody did it? Remember, after all, the state of the world as we ask this question: population growth, while declining in rate, is still relentlessly increasing; we can expect world population to double within the next 40 years; and the solutions proposedâ€" development, redistribution, the enhancement of the status of womenâ€"are comparatively slow processes, especially in cultures in which traditional values are most firmly entrenched. The population bomb keeps ticking. But suppose everybody were to use "automatic," background contraception. Even in United States, where about 78% of women use some form of contraception, nonuse, erratic use, and contraceptive failures yield the following total: in the U.S., about 50% of all pregnancies are unplanned. And of these, approximately 50% are terminated in abortion. To be sure, many of the pregnancies which were unplanned would have been planned at a later date, and certainly many of the children born of unplanned pregnancies are welcomed and loved, but it is reasonable to estimate that somewhere between 1 /2 and 1 /4 of the pregnancies now ocairring (that is, somewhere between the rate of unplanned and aborted pregnancies) would not occur were the "default mechanism" reversed and the making of a positive choice were required for pregnancy to occur. The central assumption here is that womenâ€"and parents generallyâ€"would choose to have fewer children than they would accept having if pregnancy occurred. As things now stand, half of all unplanned pregnancies are carried to termâ€"about a third of the total births in the United States. If the default mechanism were reversed, so that an extra level of choice were inserted into the natural biological process, many of these pregnancies would not be initiated in the first place. If this is so, the result of reversing the default mechanism on population growth could be dramaticâ€"even in a country, like the U.S., in which the birthrate is ...15-..