In this paper, we estimate the extent of misclassification in patent examination decisions between the EPO and JPO – that is, applications that are incorrectly refused a patent or incorrectly granted a patent. Using a proxy for inventive step as the predictor of the correct decision, we find that the probability that a “true grant” application is refused is 6.1 percent, while the probability that a “true refusal” application is granted is 9.8 percent. However, we find no evidence of an increasing trend of granting “bad” patents at the EPO and JPO.