Testing the Finch Hypothesis on Green OA Mandate Ineffectiveness

We have now tested the Finch Hypothesis. Using data from ROARMAP institutional Green OA mandates and data from ROAR on institutional repositories, we found that deposit number and rate is significantly correlated with mandate strength (classified as 1-12): The stronger the mandate, the more the deposits. The strongest mandates generate deposit rates of 70%+ within 2 years of adoption, compared to the un-mandated deposit rate of 20%. The effect is already detectable at the national level, where the UK, which has the largest proportion of Green OA mandates, has a national OA rate of 35%, compared to the global baseline of 25%.