While I think the design of the Affordable Care Act is bad, as a policy wonk I look at the implementation as having one unique silver lining. It will be the largest natural experiment on the effectiveness of insurance marketplaces ever launched.

Roughly 100 exchanges have been created, one for the individual market and small business market in each state. These exchanges vary greatly in size, design, level of competition, and public outreach. By comparing all these different exchanges once they have been running for a while we can learn what conditions have any impact.

We will see if the actual size of the risk pool matters at all by comparing small states like North Dakota to big states like Pennsylvania. I doubt the number of people will matter much as long as a minimum size is reached. Many large companies are still smaller than these state exchanges but their employee base has a sufficient-size risk poll.

We should be able to determine if aggressive public outreach makes any real difference in enrollment by comparing states like Texas which refuses to do promotion to Democratic states like California that have spent big on outreach.

It might be possible to figure out if exchanges run as an “active purchasers” exchange improve cost controls or quality by comparing active purchaser states like Oregon to federally run states like Wisconsin.

This experiment should provide some interesting data on how the level of competition impacts all aspects of insurance. There is some early indication that more insurers on the exchanges are associated with lower premiums, but that could be correlation not causation or only the result of a temporary marketing ploy. We know very few people ever change their plans once they have signed up. It could be insurers in competitive markets are setting their premium below cost in this first year but will raise them noticeable in the future once many people have basically locked in.

All current data on exchanges using only private insurers, both nationally and internationally, have strongly indicated the basic idea is a cost control failure. But since President Obama insisted on using this system policy experts might as well make good use of the mountain of data this grand exchange experiment will produce.

Map by Kurykh under Creative Commons license