The Congressional Budget Office is close to putting a price tag on some health care proposals, but Democrats, fearful that Americans may get sticker shock, are considering using estimates of the White House Office of Management and Budget instead, the Hill reports.

In the article, Democrats express concern that the CBO will inadequately value the “savings” that a proposal would generate through preventive care.

The potential cost savings from preventive health care is a thorny issue, because not all prevention is created equal. While it’s true that you could reduce health care costs if people lived healthier lives, it’s not clear that you can change people’s behavior through government policy, and as I wrote earlier today, Democratic health care proposals threaten successful private sector efforts to lower costs by cutting obesity and smoking rates. Furthermore, a number of experts have found that prevention does not save money when it takes on the form of increased screening, overdiagnosis of diseases, overprescription of drugs, and so forth, because the cost of such measures across the wider population tends to eclipse any savings generated by cutting down spending once people have a given illness.

What this means in reality, is that by using rosy assumptions about the projected savings from prevention, the White House will be able to come up with a low ball figure on the cost of health care legislation.