ObamaCare will be argued next week in the Supreme Court. While the justices will consider the intricacies of constitutional law, at their heart the arguments in favor of the legislation have to do with the economics of health care.

Consider the individual mandate to purchase health insurance. The Obama administration defends the mandate on the ground that a person's decision to not buy health insurance affects commerce by materially increasing the costs of others' health insurance. The government adds that health care is...