The Southern Baptist Convention is so large and contentious that it makes news on both the religion pages and the front pages, as when it voted a couple of years ago to boycott Disney and more recently affirmed that the Bible bars women from serving as pastors. Those who do not read the financial pages, however, may have missed a page-two article in The New York Times by Virginia Postrel, editor of Reason, on the "Economic Scene." In the June 15 newspaper, she writes "Of Conservatism and Distinctiveness in the Religious Marketplace."

Thanks to her dependence upon Professor Laurence Iannaconne, Postrel offers a different spin on Southern Baptist rulings. To condense a complex plot: He and she see these rulings as part of "niche marketing." A church body with 15.9 million members may hardly seem niche-oriented, unless one thinks of the Grand Canyon as a mere "niche." Yet the economists make a good case.

Iannoconnean "rational choice" and "marketing" theorists in respect to religious decision may miss many dimensions of religion, but they seem to be right on to a main theme: Successful religious bodies develop some sort of shtick, some way of being different, of satisfying people's needs to have boundaries drawn to show them who is in and who is out.

Where Iannaconne and his colleagues may have been dealing with an obsolete measure (ever since Dean Kelley first employed it in "Why Conservative Churches Are Growing" in the 1970s), the Southern Baptists might help them update. The issue: The rational choice, market-oriented people all but counseled religious groups that if you want to grow, make high demands, be very strict, and separate members from the larger world. But such observations and counsel do not account for the fact that most such denominations--from the "sects" to the Missouri Synod Lutherans to the Christian Reformed--don't grow.

What is more, the prospering churches, including evangelical megachurches and the like, offer more than they demand. What does one give up when being "born again" provides access to an adult world including country clubs, BMWs, or, on church property, such amenities as racquetball courts? What Iannaconne seems to be stressing now is that a group's growth and success comes less from the call for sacrifice and more from the understanding that one's group has more to offer, including boundaries.

In some surveys, Southern Baptists have abortion and divorce rates as high as any other body. Disney probably did not suffer a dollar's worth from the anti-Disney boycott. Southern Baptists may be--are?--very worldly consumers, at home in the culture, by and large. But they know how to draw symbolic lines and boundaries, and claim biblical authority in doing so, and that is appealing to many people.