The paper, written by economists Adam Elbourne and Kan Ji, was published by the Netherlands Bureau for Economic Policy Analysis, which is part of the Dutch ministry of economic affairs, the EUObserver reports.

The authors write in their paper:

We show that the identification schemes used by Burriel & Galesi (2018), Boeckx et al. (2017) and Gambacorta et al. (2014) fail to plausibly recover true unconventional monetary policy shocks in the euro area. In their identification schemes the information contained in the size of the central bank’s balance sheet is key to distinguishing monetary policy shocks from other shocks that lower financial market stress. We show that replacing the size of the ECB’s balance sheet with random numbers leads to statistically indistinguishable impulse response functions and time series of supposed unconventional monetary policy shocks. In contrast, using monetary policy shocks identified from futures rate data by Jaroci´nski & Karadi (2018), we argue that unconventional monetary policy has not had a statistically significant effect on real economic activity.