And, if analyzing the dynamics of this situation were not already complicated enough, some firms may “freeze” their systems in the middle of 1999 - effectively forgoing the installation of new hardware and software systems just before the millennium. This, too, could influence spending on computer equipment - shifting some of it from 1999 into 2000.
Parallel shifts of the Phillips curve could arise from the impacts of cost-push shocks or from a de-anchoring of inflation expectations, with different implications for monetary policy. External and domestic cost-push shocks could have led to a downward shift in the Phillips curve of the euro area.