A recurring demand that Republicans in the House of Representatives have insisted on in exchange for funding the federal government is a delay of the individual mandate provision in the Affordable Care Act (ACA). This individual mandate essentially serves as an anti-free-rider device—it ensures that people cannot just decide to start paying for health insurance after they get sick. In economic terms, this keeps the overall pool of insured people healthier and more stable, and makes the whole ACA more efficient.

A recent study has looked at both the number of people covered as well as the cost per newly covered individual under the ACA with and without the mandate. With the mandate, the ACA is projected to increase health insurance coverage by a bit over 25 million Americans when phased in. Without the mandate, this number falls to just over 11 million. Stripping out the mandate will reduce the number of people covered by more than half.

And, stripping out (or delaying) the mandate will also make this expanded coverage more expensive. With the mandate, each new enrollee will cost the federal government $3,912. Without the mandate, each new enrollee will cost almost double this much—$7,638.

While making health insurance more expensive for Americans seems like an odd priority for any faction of the House of Representatives, it should be noted that this is not the first time they’ve pursued this goal—in fact, making any health reform less efficient has been a long-running priority of GOP House members in recent years.