BRYAN CAPLAN
May 7, 2013
Keynesian Bets: What's Out There
May 6, 2013
Keynesian Bets Bleg
May 6, 2013
The Pyramid of Macroeconomic Insight and Virtue
May 2, 2013
A Natalist Provision
May 1, 2013
I Was a Teenage Misanthrope
DAVID HENDERSON
May 5, 2013
John Thacker on Vaccinations and the Sequester
May 3, 2013
Chef Rudy's Virtues Project
May 2, 2013
My take on Reinhart and Rogoff
May 1, 2013
Medicare Kills a Program


Note his 'this issue'.
Right on Sully
I think I can agree with Sumner's view as long as it is confined to certain types of questions, like China's GDP vs USA's GDP, where there really is no clear answer. We each have an opinion and over time there is a convergence until the truth really is indisputably clear (say, exchange rate GDP in China>USA's).
On more objective issues like NGDP is growing slowly, printing will make it grow faster there is less (or no) room for truth to be socially constructed. So why not be like Sumner and use Rorty's maxim where applies?
Right now people regard it as "true" that the Fed had an easy money policy in 2008. I hope to change that perception, so that it will no longer be regarded as true. As far as what is "really true," where do we find that information?
There is no objective way to determine whether the US or China has a larger PPP GDP, because the term PPP GDP has never been adequately defined. Is it America's output at Chinese prices, or Chinese output at American prices? And how do you adjust for quality differences when there is no output selling in some American markets at Chinese quality levels.
This is why Rortyism, despite its seeming perniciousness, turns out to be harmless in practice: No one, including Rorty, acts the way you'd expect him to act if he really believed it. (If Sumner really believed it, he wouldn't have written "I hope to change that perception, so that it will no longer be regarded as true"; he would have written, "I hope to change that perception, so that it will no longer be true.")
Sumner wrote:
"I think the best way to approach this issue is to use Rorty's maxim..."
Patrick Sullivan is correct.
Since when do we read "this issue" as "plus every other unrelated thing"?
If you want to argue with Sumner, keep it to: "no, not even this admittedly subjective and arguable measure -- which we in fact recently dramatically revised by consensus -- is socially constructed."
Or perhaps: "No, Scott, nothing at all is socially constructed".
Otherwise you are having an off day.