Testing for EPO directly is difficult because the synthetic version is almost indistinguishable from its natural form - a version of the hormone was originally created to treat severe anaemia.
In fact, the Air Force has already begun testing a program to certify coal-based synthetic fuels for the B-52 bomber, a process that may lead to synthetic fuel use in all of its planes.
The researchers tested the impact of the bailout a number of ways, including moving the bailout date and testing the impact on individual companies instead of the synthetic composite.