J. Bradford DeLong's Blog, page 297
September 28, 2018
Thomas A. Russo (2008): Credit Crunch: Where Do We Stand?...
Thomas A. Russo (2008): Credit Crunch: Where Do We Stand?: "The recent market has been, in many respects, worse than it was in August. The lack of confidence in pricing has led most buyers away from mortgage products, and there are few buyers in the market with both the balance sheet and expertise to understand any 'bargains'...
...Some things that might be done are... legal clarity that the fundamental policy for dealing with the subprime issue should involve broad-brush approaches rather than traditional loan-by-loan analyses.... Programs should be targeted to homeowners (not investors) with ARMs who are or will become delinquent as a result of resets and are unable to refinance because of credit issues or property value declines.... Since the U.S. housing stock is worth about $23tr (or about $10tr more than annual U.S. GDP) a drop of 15% would reduce wealth by about $3.5tr. Policy-makers should carefully evaluate opportunities to reverse the trend in this diminution of wealth and, thereby, also stimulate all the by-products of the housing industry.... A lot is at stake for the economy, and all actions that add liquidity or help prevent distressed sales that exacerbate the problem, are worthy of consideration (even if they are somewhat ���out of the box���). Emphasis should be placed on developing a portfolio of actions, some of which could be temporary in nature, rather than finding a magic bullet!...
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2018Q2GDP: Paul Krugman: @PaulKrugman: "I'm still on vaca...
2018Q2GDP: Paul Krugman: @PaulKrugman: "I'm still on vacation, but did see this morning's economic number. Lots of stuff to say about why it's no big deal, but this picture captures most of it...
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September 27, 2018
Arindrajit Dube and friends have a pick-up discussion on ...
Arindrajit Dube and friends have a pick-up discussion on how to characterize the impact of employer monopsony power: Arindrajit Dube: @arindube: "I think growing evidence suggets "laissez faire" equilibrium is monopsonistic. So shocks like de-unionization, outsourcing and eroding wage norms can push down pay in ways hard to understand with competitive lab mkts. But the shock may not be increased concentration itself...
...Larry Mishel: Yes, many policy decisions (including omissions) have weakened workers' leverage so it is as if there were literal monopsony or labor market concentration. I call it 'metaphysical monopsony' but don't expect the phrase to catch on.
Arindrajit Dube: No, I don't expect it to either :-) But I appreciate the effort!
Kate Bahn: I call it (and I think others do too, like @dougwebberecon) call it "dynamic monopsony"! Economists like the word dynamic, but I'm not sure if non-economists understand what that means either.
Larry Mishel: That's the Alan Manning term. But I think it is narrower than what I have in mind, which is all the ways the playing field was tilted against workers....
Ben Zipperer: It is interesting to see the identification of monopsony with concentration, especially given that the classic text by Joan Robinson is clear that monopsony is much broader....
Noah Smith: I was just going with "employer power" in my posts...
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IMHO, this is closely akin to William Julius Wilson's "th...
IMHO, this is closely akin to William Julius Wilson's "the declining significance of race"���i.e., the rising significance of class: Robert Manduca: How rising U.S. income inequality exacerbates racial economic disparities: "In 1968... median African American family income was 57 percent of the median white American family income. In 2016, the ratio was 56 percent. The utter lack of progress is striking...
....puzzling because racial gaps in many other social outcomes have contracted since the 1960s: College attainment, high school test scores, and life expectancy all have seen some convergence between blacks and whites, though progress in these areas is by no means complete.... The intransigent racial income gap is the result of two opposing trends. On the one hand, blacks have made real progress climbing to higher positions on the income distribution. From 1968 to 2016, the median African American climbed from the 25th percentile of the national family income distribution to the 35th percentile. While this progress is nowhere near complete, it was enough to narrow the gap in income ranks between blacks and whites by almost a third. In the 1960s, the large majority of whites earned more than the typical black person. By 2016, that proportion had declined substantially. This progress came despite continued racial disparities in parental wealth, access to educational resources, and treatment in the labor market.
On the other hand, just as African Americans were entering the ranks of the middle class in large numbers for the first time, broader economic forces were undermining the financial security of families across all races. Starting in the 1970s, changes to the economy and to public policy began concentrating a larger and larger share of national income in the pockets of the richest members of society. Incomes for the middle class and the poor have hardly grown at all, while incomes for the richest 1 percent almost tripled.
These changes to the income distribution mean that as more African Americans succeed in overcoming the many obstacles to reaching the middle class, the payoff is not as great as it had been for social groups that climbed the income ladder earlier in U.S. history...
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Duncan Black: Remember When Bill Clinton Ended Welfare As...
Duncan Black: Remember When Bill Clinton Ended Welfare As We Know It And Took That Off The Table Forever?: "There's barely anything resembling 'welfare' (aside from rich people welfare) but that doesn't stop them: '(CNN) Republican Rep. Jason Lewis has repeatedly demeaned recipients of welfare and government assistance, calling them "parasites" and "scoundrels," and said the black community had "traded one plantation for another.' Conservative white people believe there's a secret welfare system for black people. You cannot convince them otherwise, no matter what you do..."
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"[All of] his college acquaintances who weren't part of t...
"[All of] his college acquaintances who weren't part of the hard-partying prep school crew though [Kavanaugh] was an incredible ass----. And he was an ass---- when he was working for Ken Starr and an ass---- when he was part of hacking and stealing Democrats' emails in the 2000s. And an ass---- as a judge, e.g. the SeaWorld case that Steve Greenhouse wrote about recently. That's the word David Rothkopf uses, and I think it's the word that all information, even dubious freshman memories, supports..."
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Wigner has many friends, and they can disagree: Daniela F...
Wigner has many friends, and they can disagree: Daniela Frauchiger and Renato Renner: Quantum Theory Cannot Consistently Describe the Use of Itself. Lidia del Rio: Journal club: Frauchiger-Renner No-Go theorem for Single-World Interpretations of Quantum Theory: "In this talk I will go over the recent paper by Daniela Frauchiger and Renato Renner, "Single-World Interpretations of Quantum Theory Cannot Be Self-Consistent" (arXiv:1604.07422)...
...The paper introduces an extended Wigner's friend thought experiment, which makes use of Hardy's paradox to show that agents will necessarily reach contradictory conclusions-unless they take into account that they themselves may be in a superposition, and that their subjective experience of observing an outcome is not the whole story. Frauchiger and Renner then put this experiment in context within a general framework to analyse physical theories. This leads to a theorem saying that a theory cannot be simultaneously (1) compliant with quantum theory, including at the macroscopic level, (2) single-world, and (3) self-consistent across different agents. In this talk I will (1) describe the experiment and its immediate consequences, (2) quickly review how different interpretations react to it, (3) explain the framework and theorem in more detail...
Scott Aaronson: It���s Hard to Think When Someone Hadamards Your Brain: "So: a bunch of people asked for my reaction to the new Nature Communications paper by Daniela Frauchiger and Renato Renner, provocatively titled 'Quantum Theory Cannot Consistently Describe the Use of Itself'...
...While I found their paper thought-provoking, I reject the contention that there���s any new problem with QM���s logical consistency: for reasons I���ll explain, I think there���s only the same quantum weirdness that (to put it mildly) we���ve known about for quite some time.... The new argument rests on just three assumptions... QM works, measurements have definite outcomes, and the ���transitivity of knowledge���... if you reject the argument, then you must reject at least one of the three assumptions; and how different interpretations (Copenhagen, Many-Worlds, Bohmian mechanics, etc.) make different choices about what to reject. But I reject an assumption that Frauchiger and Renner never formalize.�� That assumption is, basically: ���it makes sense to chain together statements that involve superposed agents measuring each other���s brains in different incompatible bases, as if the statements still referred to a world where these measurements weren���t being done���....
The argument can be understood as simply the ���Wigner���s-friendification��� of Hardy���s Paradox.... Take Hardy���s paradox from 1992, and promote its entangled qubits to the status of conscious observers who are in superpositions over thinking different thoughts.�� Having talked to Renner about it, I don���t think he fully endorses the preceding statement.�� But since I fully endorse it, let me explain the two ingredients that I think are getting combined here���starting with Hardy���s paradox, which I confess I didn���t know (despite knowing Lucien Hardy himself!) before the Frauchiger-Renner paper forced me to learn it.... If you strip away the words and look only at the actual setup, it seems to me that Frauchiger and Renner���s contribution is basically to combine Hardy���s paradox with the earlier Wigner���s friend paradox.�� They thereby create something that doesn���t involve counterfactuals quite as obviously as Hardy���s paradox does, and so requires a new discussion...
My attempt to understand: We have Alice, Bob, Wigner, Wigner's Friend, and Wigner's Other Friend...
Prepare the state $ |\psi\rangle $:
$ |\psi\rangle = \frac{|������\rangle + |������\rangle
+ |������\rangle}{\sqrt{3}} $
Alice measures the first qubit; Bob measures the second.
Conditional on Alice's qubit being in state |������:
$ |Bob\rangle = \frac{|���\rangle + |���\rangle}{\sqrt{2}} = |���\rangle $
so Bob can never see $ |���\rangle = \frac{|���\rangle - |���\rangle}{\sqrt{2}} $.
Conditioned on Bob���s qubit being in the state |������:
$ |Alice\rangle = \frac{|���\rangle + |���\rangle}{\sqrt{2}} = |���\rangle> $
so Alice can never see $ |���\rangle = \frac{|���\rangle - |���\rangle}{\sqrt{2}} $.
Since there is no $ |������\rangle> $ component in the state, either Bob or Alice must be |������. Therefore either Alice or Bob must be $ |���\rangle $ Therefore we can never see $ |������\rangle $ when Alice and Bob measure. Yet we do, 1/12 of the time.
So now we Wignerize it:
Alice measures ������.
Wigner observes, writes "I have observed Alice's measurement and drawn the appropriate conclusions about whether Bob can see $ |���\rangle $", and leaves that message behind.
Wigner departs beyond an event horizon, leaving no possibility of decohering with the rest of the universe.
A quantum eraser is applied to Alice and her particle.
Bob measures ������.
Wigner's friend observes, writes "I have observed Bob's measurement and drawn the appropriate conclusions about whether Alice can see $ |���\rangle $", and leaves that message behind.
Wigner's friend departs beyond an event horizon, leaving no possibility of decohering with the rest of the universe.
A quantum eraser is applied to Bob and his particle.
Off beyond their event respective event horizons, either Wigner is in the state $ \frac{|������\rangle + |������\rangle}{\sqrt{2}} $ or Wigner's friend is in the state $ \frac{|������\rangle + ||������\rangle}{\sqrt{3}} $, and so either Wigner or Wigner's friend knows Bob or Alice, respectively, cannot have seen $ |���\rangle $ .
You, knowing what one of Wigner and Wigner's friend knows beyond their respective event horizons, use the "consistent reasoning" heuristic to conclude that $ |������ \rangle $ is impossible.
Alice and Bob then measure ������.
Wigner's other friend looks, and 1/12 of the time sees a fully decohered $ |������ \rangle $.
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September 26, 2018
Hal Varian: Bots vs. Tots: "US labor market is already be...
Hal Varian: Bots vs. Tots: "US labor market is already beginning to tighten. Expect a tight labor market for the next 15-25 years. Retirees continue to consume. Robots don���t consume. Labor supply is growing more slowly than labor demand. Old intuitions no longer helpful...
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Equitable Growth: TONIGHT! Join us for #ResearchOnTap: Ec...
Equitable Growth: TONIGHT! Join us for #ResearchOnTap: Economic mobility: The impact of race and place, ft. #EGgrantee(s) @InequalityHKS���s Ellora Derenoncourt, @DavidGrusky & @TrevonDLogan w/ @KA_Marketplace: 919 19th Street NW, Washington, DC 20006 6-8 PM
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Josh Marshall: @joshtpm: "Even before this came up, Brett...
Josh Marshall: @joshtpm: "Even before this came up, Brett Kavanaugh seems to lie a lot. The stuff with the Manny Miranda hacking scandal is what really stood out to me. Aside from denying the central accusations, he���s even more obviously lying about the ���Renate alumni��� stuff...
...His claim there is transparent b---s---. It���s obvious he and his crew had some sort of slut shaming thing with this then-girl. He lies so routinely that it really extinguishes whatever small doubt I might have that Ford���s accusation could be wrong or that the incident was somehow remembered radically differently vy the two people. He just seems to lie routinely. That sounds like a jaundiced take. But I think it���s really hard to deny. And that means that his flat denials of these incidents are meaningless...
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