As Washington policymakers continue to question the value of global airline alliances, Continental Airlines has shown them a benefit they most likely never suspected: increasing the transparency of sensitive data tightly held by many carriers.

That may not have been what Continental set out to do, but it’s a positive side effect. The very day it officially joined the Star Alliance last week, it uploaded on its Web site “award” seats made available by other alliance members, which its customers can book using Continental frequent-flier miles. It took “nine months of planning and implementation”…