If there's one thing the WSJ editorial page loves, it's arguments that the extension of jobless benefits creates unemployment by discouraging people to find work.

And so it is today that Harvard economist Robert Barro is out with a new piece arguing that if Obama hadn't extended unemployment benefits, we'd be at 6.8% unemployment and not 9.5%.

How does he arrive at this number? Simple, he just presumes for no reason that the nature of the recent jobless spike is no different than the one seen in the early 80s.

(An examination of unemployment in the early 80s vs. right now was made recently by David Leonhardt in the NYT. He noted that in 1982, 22% of the population experienced joblessness, whereas this time that peaked at 16%).

So anyway Barro just says: Well, unemployment fell fast in the early 80s, when we had a shorter period of being able to collect benefits, ergo, it should be the same now.

Here's Barro:

To begin with a historical perspective, in the 1982 recession the peak unemployment rate of 10.8% in November-December 1982 corresponded to a mean duration of unemployment of 17.6 weeks and a share of long-term unemployment (those unemployed more than 26 weeks) of 20.4%. Long-term unemployment peaked later, in July 1983, when the unemployment rate had fallen to 9.4%. At that point, the mean duration of unemployment reached 21.2 weeks and the share of long-term unemployment was 24.5%. These numbers are the highest observed in the post-World War II period until recently. Thus, we can think of previous recessions (including those in 2001, 1990-91 and before 1982) as featuring a mean duration of unemployment of less than 21 weeks and a share of long-term unemployment of less than 25%.

These numbers provide a stark contrast with joblessness today. The peak unemployment rate of 10.1% in October 2009 corresponded to a mean duration of unemployment of 27.2 weeks and a share of long-term unemployment of 36%. The duration of unemployment peaked (thus far) at 35.2 weeks in June 2010, when the share of long-term unemployment in the total reached a remarkable 46.2%. These numbers are way above the ceilings of 21 weeks and 25% share applicable to previous post-World War II recessions. The dramatic expansion of unemployment-insurance eligibility to 99 weeks is almost surely the culprit.

To get a rough quantitative estimate of the implications for the unemployment rate, suppose that the expansion of unemployment-insurance coverage to 99 weeks had not occurred and—I assume—the share of long-term unemployment had equaled the peak value of 24.5% observed in July 1983. Then, if the number of unemployed 26 weeks or less in June 2010 had still equaled the observed value of 7.9 million, the total number of unemployed would have been 10.4 million rather than 14.6 million. If the labor force still equaled the observed value (153.7 million), the unemployment rate would have been 6.8% rather than 9.5%.

This is really, really thin, because it presumes that the different lengths of being able to collect unemployment-insurance is the defining difference between now and then. But in 1982 we weren't coming off a massive multi-year bubble. And we're not merely in a post-burst era -- home values are still going down, and construction is at something of a standstill, which means this is an active drag on the economy.

Housing is just one difference, but as this chart from Calculated Risk -- which compares housing starts and employment -- reminds us, it's a powerful predictor of jobs. And sure, it's probably not the only issue, but Barro could at least try to argue why this is not a relevant factor to consider before decrying the jobless benefits that can represent the last barrier between joblessness and total devastation for many families.