We had been expecting Senate Majority Leader Harry Reid to unveil the full Senate’s version of the healthcare reform bill last week, but today there is word that it may not even be released this week. While the specific reasons for the delay have not been disclosed, we suspect he is having difficulty balancing the need to rein in the total cost of the bill against the need to keep health insurance premiums low enough to attract the participation of relatively healthy middle-income Americans who currently lack health insurance.

For example, one criticism of the Baucus bill was that it did not provide sufficiently generous subsidies for middle-income Americans to purchase health insurance, even though limiting the subsidies helped lower the overall cost of the bill. For single Americans with income of $40-50,000, for example, the annual cost of purchasing health insurance in the new exchanges to be established is estimated to be approximately $5,000. There is a concern that younger and healthier Americans in that income range who lack health insurance may decide not to purchase health insurance. In fact, because new regulations would prevent insurance plans from excluding pre-existing conditions, nothing would prevent these Americans from purchasing insurance after they realized that they were sick. Accordingly, they may feel that there is little incentive for them to purchase insurance.

While an individual mandate that imposed high penalties on individuals who did not purchase insurance might avoid this “free rider” problem, Democratic leaders in Congress are reluctant to impose high penalties on middle-income Americans who do not purchase health insurance, particularly if the health insurance policies are not perceived to be easily affordable. High penalties would be politically unpopular, as well. Low penalties, however, are not likely to provide a sufficient incentive to purchase insurance.

One possible result would be that relatively young and healthy Americans who currently lack health insurance would choose not to participate in the insurance exchange, so that the insurance pool would consist of relatively unhealthy Americans with higher healthcare costs, thereby driving up average premium costs. As average premium costs rise, even fewer healthier Americans would choose to participate

To avoid this outcome, Senator Reid will need to find the right mix of subsidies as well as penalties associated with the individual mandate, all while reining in the overall cost of the bill. That it is a difficult needle to thread.