That is because potential output is not something that can ever be observed and directly verified; we infer it from the behavior of other variables, including prices themselves, that we do observe. Estimating potential output and slack also is complicated by changes over time in labor and product markets that alter the degree of resource utilization that is consistent with stable inflation.
At the same time, subdued labour market conditions and precautionary household saving are weighing on consumer spending. Weak business prospects and high uncertainty are dampening investment, while the weakness in the global economy is hampering foreign demand for euro area goods and services.