The paper considers tests for the presence of a random walk component in a stationary or trend stationary time series and extends them to series which contain structural breaks. The locally best invariant (LBI) test is derived and the asymptotic distribution obtained. Then a modified test...

This paper investigates agglomeration economies in an annual panel of NUTS 2 and NUTS 3 city regions across France, Germany, Ireland, Italy, Spain and the UK over 1980-2006 and comparing three sub-samples to see if the effects have changed over time. We uncover evidence of long run agglomeration...