It is perfectly reasonable to take the peak year of '73, since it marks a break from the previous, positive trend. The point PK is making is that we are living under a different trend. 1973 or thereabouts is a milestone in US economic history because it marks the beginning of the productivity slow-down, as well as anticipating a trend of growing inequality.
Different data sources are appropriate depending on the question you are trying to answer.
mbs
>
> I've read LBO for a while now--trying to 'learn me' some economics--and
> i've never posted before but I happened upon a question I thought might
> best be answered here. I found a critique
>
(http://www.poorandstupid.com/2003_12_21_chronArchive.asp#10720429423960995
> 8) of Krugmans latest article in the nation: "The Death of Horatio
> Alger." His main point seemed to be Krugman selectively used the data by
> choosing a year bad year to begin at. My first question is, is there
> anything to this attack? My second question is about the fact that you
> obviously have to choose some date to begin analysis so what is the common
> consensus (I know there probably isn't any) economist have come to about
> dates to use? Is it simply a matter of all economist massaging data to
> back up their assumptions? Any thoughts on the matter would be
> appreciated.
>
> Jim
> http://www.JimN4.blogspot.com
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