A. Fatas weist auf seinem Blog darauf hin, dass der IWF aktuell schätzt, dass Italien zwischen 1990 und 2009 durchgängig eine positive Produktionslücke aufwies.
Zur besseren Einordnung füge ich noch die Arbeitslosenquote über den gleichen Zeitraum hinzu, die stark schwankt, aber eigentlich nicht den Schluss zulässt, dass sie die ganze Zeit unterhalb der NAIRU lag:
Passt irgendwie nicht zusammen, oder? Bzw. die lange Überkapazität muss aus der Partizipationsrate oder der Produktivität kommen.
Für mich ist dies wieder ein Beispiel dafür, dass die aktuellen Methoden/Modelle zur Unterscheidung von Wachstums- und Konjunkturaspekten mit der Großen Rezession nicht zurande kommen.
"Since the crisis started not only we have changed our views about the future but we have also changed our views of the past. If you look at the blue line you can see that in 2009 we thought that the Italian economy had been growing at a rate similar to potential output for the previous 19 years (and remember that growth rates in Italy were already low during most of these years). But today we believe that Italy was producing "too much" during all those 19 years (with the exception of 1993). Every single year Italy was somehow employing too many workers or those workers where being too productive. Why that change? Because of the interpretation that some (most?) of the GDP fall during the crisis will be permanent and to make this consistent with what happened before the crisis we need to lower out estimates of potential output in those years as well. Let me me be clear, we have no theory and no direct evidence that potential output during those years was lower than what we thought before, we are simply finding a way to validate the current level of output that seems to be going nowhere. And because it GDP refuses to grow it must be permanent and structural.
The alternative (and much more depressing) interpretation is that a crisis, which is clearly global in its nature, this is not an Italian crisis, has resulted in a a very long period of low growth. This low growth has had an effect on potential output because long-term growth rates cannot be completely separated from cyclical conditions. Labor market conditions have an effect on long-term unemployment, discouraged workers and participation rates (what Blanchard and Summers called backed in 1986 hysteresis in labor markets). But even more fundamentally, investment rates, technology adoption are slowed down by cyclical conditions and these are the forces that drive potential growth rates. So the longer is the recession, the bigger the impact on potential output."