Over the period 2003 to 2018, the average of the size of the shadow economy of the 28 EU-countries decreased from 22.6% (of GDP) in 2003 to 16.8% in 2018. With respect to a decrease or increase in 2018, the development of the shadow economy in these EU-countries is not uniform. In most EU-countries (23 out of 28), the shadow economy will further decrease, but the remaining 5 EU-countries (Bulgaria, Croatia, Hungary, Romania, and UK) it will increase.