Should-Read; Andrew Gelman: Using black-box machine learning predictions as inputs to a Bayesian analysis

Should-Read; Andrew Gelman: Using black-box machine learning predictions as inputs to a Bayesian analysis: “We started by using the output from the so-called machine learning as a predictor… http://andrewgelman.com/2017/09/20/using-black-box-machine-learning-predictions-inputs-bayesian-analysis/

…then we fit a parametric model to the machine-learning fit, and now we’re transitioning toward modeling the raw data. Some interesting general lessons here, I think. In particular, machine-learning-type methods tend to be crap at extrapolation and can have weird flat behavior near the edge of the data. So in this case when we went to the parametric model, we excluded some of the machine-learning predictions in the bad zone as they were messing us up…

Must-Read: Chandrasekhar Ramakrishnan: The DeLong-Shiller Redux

Must-Read: Above a Shiller CAPE of 25, we have essentially three observations as to what happens next. Hence “we have little idea what is likely, and past performance is not a reliable guide to future results” is the only sound thing to say. As Jim Powell says: with two data points you have an estimate of the mean and an estimate of the standard error, for you think your two data points are at μ ± σ/2. And then he laughs:

Chandrasekhar Ramakrishnan: The DeLong-Shiller Redux: “2014, Robert Shiller and Brad DeLong…. [Shiller] claims if the value of this [CAPE] ratio is above 25, a major market drop is probably brewing…

…[DeLong] writes “we find that we cannot calculate a ten-year return for the 2007 CAPE peak of 27.54 — we still have three years to go.” Those three years have in the meantime transpired, and we now have the data necessary to calculate the ten-year return for May 2007, when the aforementioned peak occurred. This seems like a good time to revisit the DeLong-Shiller argument….Earnings/price can… be estimated as 1/CAPE. He calls the EMH-expected-returns for a given value of CAPE “warranted returns”, and to visualize his framework, DeLong constructs the following plot, which I’ve updated to include the latest data. This plot shows CAPE vs. 10-year returns and includes a curve to indicate the warranted returns. Reflecting on the fit of the curve, DeLong remarks, “Given the naiveté of the framework, that turns out to be… a remarkably good guide to the central tendency of the distribution of future ten-year returns conditional on the CAPE.” And I would have to agree….

The DeLong Shiller Redux Chandrasekhar Ramakrishnan Medium

Past performance is not an indicator of future performance. Nonetheless, we can see what past performance at today’s CAPE levels would yield. We have earnings data up to the end of Q2 2017 and using that, we can compute CAPE and try the following impossibly naïve model: for a current CAPE value (for which we do not yet have returns data), take the 19 closest values in the past and average these to get a prediction. This is of course not how machine learning should be done…

The DeLong Shiller Redux Chandrasekhar Ramakrishnan Medium

I should point out that my “warranted” returns are for somebody reinvesting their portfolio and holding to ∞, thus eliminating valuation-ratio risk and valuation-ratio mean reversion from the problem. They also assume that reinvested earnings are neither dissipated in corporate empire building nor able to earn supermarket returns via superior information.

When CAPE is high and when your horizon is less than ∞, you should incorporate some estimate of valuation-ratio mean reversion—and that is what Ramakrishnan does…

Must-Read: Larry Summers: One last time on who benefits from corporate tax cuts

Must-Read: I confess that I, at least, never heard Larry Summers say: “A-list people do not directly criticize A-list people: doing so is a way to become a B-list person”. I doubt he has ever said it that way.

I have, however, heard Larry say—many times—that it is in general not wise to presume bad faith or incompetence on the part of, say, present or former fellows at places like, say, the American Enterprise Institute.

First of all, people think differently and disagree. Economics ain’t rocket science. As John Stuart Mill said, in economics:

What was affirmed by Cicero of… philosophy… may be asserted without scruple… that there is no opinion so absurd as not to have been maintained by some person of reputation. There even appears to be on this subject a peculiar tenacity of error—a perpetual principle of resuscitation in slain absurdity…

You might be the one maintaining the absurd position. You should keep an open mind, and mark your beliefs to market.

Second, strident criticism of error according to a hermeneutics of bad faith or a hermeneutics of incompetence may be effective at rallying one’s own troops to the cause, but it is not effective in winning converts from the other side, or even at persuading the rational middle of good-hearted and public-spirited people fresh to the issue.

Thus, the view was, we should invite Kevin Hassett to present his view of the “Tax Reform” framework to the Tax Policy Center, and name him a Distinguished Speaker. We should presume that Charles Murray’s rantings are not at base motivated by whatever made him burn a cross in imitation of the KKK. We should presume that there is competence at some level behind Casey Mulligan’s claim that 4% of the American labor force quit their jobs and began happily playing video games in the basement as a result of the passage of ObamaCare and similar policies. We should take it for granted that John Cochrane has done his math correctly when he claims that a 20% VAT could provide a progressive replacement to America’s tax system. We should keep a open mind to Nick Eberstadt’s argument that Americans have been unmanned by their receipt of unemployment insurance, Medicaid, Medicare, and Social Security—never mind the fact that such programs neither greatly alter incentives nor are perceived as “welfare” by beneficiaries—and turned into a nation of “takers”, in the phrase coined by right-wing goldbug loon Edmund Contoski. And we should spend our time and energy going the extra mile to presume that their positions are advanced in competence and good faith, and arguing earnestly against the positions they advance with evidence and logic, in one gigantic interminable game of whack-a-mole.

I have long thought that Larry was wrong here.

I have long thought that the best working rule is: everybody gets three strikes—three mistakes that are highly unlikely to have been made by someone working competently and in good faith, with plenty of opportunities to recant, correct error, and mark beliefs to market.

After three strikes, they are out. After they have struck out, then it is not irresponsible to work according to a hermeneutics of bad faith or incompetence. Rather, it is irresponsible not to.

Not to do so—to assume good faith and competence where it is absent—is, IMHO, very destructive of the public sphere in the long run. It sets in motion a downward Gresham’s Law spiral. Those who are willing to argue in bad faith are not constrained in the degree to which their doctrines can please their political masters and their think-tank donors. Those who are not competent are, similarly, unconstrained by reality—and pure fantasy can, also, often be very pleasing to political masters and think-tank donors. And so bad economists will drive out good ones: in the esteem of their political masters, in their positions in think tanks, in the financial support that they can elicit.

Larry might have thought—he has never argued this way to me, but it is a plausible argument—that it is the business of economists on each political “side” to police their own, and require quality analysis. And in the center and on the center-left there is indeed such a tendency. Charlie Schultze in the 1980s had no tolerance for the arguments of Bob Reich, who he thought dangerously overestimated the administrative and planning competence on the one hand and the relative autonomy from industry-specific rent-seeking on the other of the American government. When the smart and well-intentioned Gerry Friedman put forth a series of arguments that my faction thought greatly overstated the good that could be done by a not too massive public investment and spending program, the smackdown was intense. The view is that analyses that are not in the range of those made by politically-disinterested analysts and forecasters who do not have a career-making or -breaking dog in the fight are not analyses that should be used for policy planning or policy advocacy.

But there is no much less policing of intellectual quality on the right than on the center and the center-left. And so the downward Gresham’s Law quality-of-economic-analysis spiral continues.

It gives me no pleasure to watch the evenhanded, hermaneutics-of-good-faith-and-competence Larry vanish. But he has. And now we have a different Summers: one who is downright shrill:

Larry Summers: One last time on who benefits from corporate tax cuts: “I recently asserted that Kevin Hassett deserved a failing grade for his ‘analysis’ projecting that the Trump administration proposal to reduce the corporate tax rate from 35 to 20 percent would raise the wages of an average American family between $4,000 to $9,000…

Larry states that in his view it is Kevin Hassett who crossed the ultimate line in terms of tone and respect, and that that line-crossing deserves universal condemnation:

Hassett had, for what seemed like political reasons, impugned the integrity of people like Len Burman and Gene Steuerle who have devoted their lives to honest rigorous evaluation of tax measures by calling their work “scientifically indefensible” and “fiction”…

And this line-crossing imposes on analysts a duty to call Hassett’s garbage analysis what it is, rather than to presume it is both competently done and made in good faith:

The analysis from Hassett, chief of the White House Council of Economic Advisers (CEA), relies heavily on correlations between corporate tax rates and wages in other countries to argue that a cut in the corporate tax rate would boost returns to labor very substantially…. The CEA ignores our own historical experience…. The corporate tax cuts of the late 1980s did not result in increased real wages…. The same is true in the United Kingdom…. These examples feel far more relevant to the corporate tax issue analysis than comparisons to small economies and tax havens like Ireland and Switzerland upon which the CEA relies…. No one has defended the 4,000 dollar[/year wage boost] claim [of Hassett’s] as a “very conservatively estimated lower bound,” let alone endorsed the plausibility of the $9,000 claim…. The Wall Street Journal… published two very optimistic versions of what the wage increase could be… below CEA’s lower bound…

Then Larry turns to those who have… not defended Hassett, but not criticized Hassett either: who have, while not endorsing his numbers, tip-toed up to the line of what they think they can do in terms of providing half-hearted support for Hassett:

Casey Mulligan and Greg Mankiw… make use of simple academic abstract models that do not capture the complexities of a policy situation to argue that wage increases could be larger than the tax cut…

Let me skip over Mankiw for the moment, and go to Summers on Mulligan and company:

Mulligan accuses me of rejecting the results of my 1981 paper on Q Theory which he claims to like and teach. I’m flattered that he appreciates my paper, but am fairly confident he draws the wrong conclusions…. One central aspect… was the recognition that the corporate tax rate is… not a sufficient statistic for assessing the impact of the corporate tax system…. It is necessary to build in assumptions about depreciation allowances, debt finance and so forth…. The main point… which Mulligan entirely ignores, was that because of slow adjustment costs, the impact of tax changes was felt primarily on asset prices for a long time…. The primary impact of a corporate tax cut would be to raise after-tax profits and the stock market. This in turn, as I noted, primarily benefits wealthy individuals….

It is worth noting that Larry Kotlikoff and Jack Mintz’s response to criticisms of the Trump tax plan suffers from the same deficiencies as Mulligan’s. The authors include no corporate tax detail, no recognition of the impact of the tax proposal on asset prices, and no treatment of the budget consequences of tax cuts. The newest, boldest bit of claim inflation regarding the tax bill comes from the Business Roundtable: “a competitive 20 percent corporate tax rate could increase wages sufficient to support two million new jobs.” This would, coupled with job growth projected even in the absence of a corporate rate cut, take the unemployment rate well below 3 percent! I would be very interested to see the underlying analysis.  I would be surprised if it is convincing…

Mulligan has long seemed to me to be far past his three strikes:

And Summers on Mankiw:

Mankiw’s blog is a fine bit of economic pedagogy. It asks students to gauge the impact of a corporate rate reduction on wages in a so called “Ramsey” model or equivalently in a small fully open economy, with perfect capital mobility. Even with these assumptions, he does not get answers in the range of the CEA’s estimates. As a device for motivating students to learn how to manipulate oversimplified academic models, Mankiw’s blog is terrific as one would expect from an outstanding economist and one of the leading textbook authors of his generation…

I would not have used the word “terrific” (or “gorgeous”). I think that the Greg we have here is not primarily (1) Greg-teaching-students-about-public-finance-issues but rather (2) Greg-going-as-far-as-he-believes-he-can-to-be-helpful to the Republican Party. And I wish we had (1) Greg instead.

Why do I think this? First of all, as John Maynard Keynes wrote in his obituary for Alfred Marshall:

The study of economics does not seem to require any specialised gifts of an unusually high order…. Yet good, or even competent, economists are the rarest of birds. An easy subject, at which very few excel! The paradox finds its explanation, perhaps, in that the master-economist must… reach a high standard in several different directions… be mathematician, historian, statesman, philosopher… understand symbols and speak in words… contemplate the particular in terms of the general, and touch abstract and concrete in the same flight of thought…

And the most important element of this combination needed to be a good economist is to choose the right model for one’s analysis.

Greg begins his analysis of the effects of a corporate tax cut on the U.S. with “an open economy…”. In so beginning he has already served his readers ill. The U.S. is not a small open economy. You choose a model that applies, not a model that does not apply.

The second most important element of this combination is that one chooses a complete model and does a complete analysis. Corporate tax cuts are cut, yes. But then what? There is a government budget constraint there somewhere—or if there isn’t, that is a very important element of the situation. Is government spending cut? Is it cut now or in the future? Are other taxes raised? Which taxes? And when? Kevin Hassett called the Tax Policy Center’s analysis “scientifically indefensible” and “fiction” in large part because they had done a complete analysis, filling in the parts of the tax cut framework that were missing with what seemed to them to be reasonable assumptions. But Mankiw doesn’t do a complete analysis. The corporate tax rate is cut. Full stop.

Third, there is a math error in Greg’s presentation. When in a small open economy you cut the corporate tax rate t by an infinitesimal amount dt, that tax rate cut has three first-order effects on tax revenue. It (a) reduces how much revenue is collected from each dollar of tax base, (b) reduces production and the tax base by reducing the pre-tax rate of profit, and (c) raises the tax base by encouraging more investment. The “static” revenue-loss calculation ignores term (c). The first-order “static” revenue loss is then:

Monday Smackdown Larry Summers on Kevin Hassett and Company

But Greg misses term (b), and so he calculates the revenue loss as:

Monday Smackdown Larry Summers on Kevin Hassett and Company

This error inflates Mankiw’s calculations by a factor of 1/(1-t).

He thinks that he is demonstrating that the gain in wages is greater than the “static” revenue loss because the cut in taxes calls forth extra investment and higher productivity. But you can recognize that this interpretation is wrong by considering the case in which more capital is useless and unproductive. In that case, note that Mankiw’s math still claims that wages grow by a factor 1/(1-t) bigger than the corporate revenue loss even when the tax cut does not induce any extra investment at all.

This is the kind of math error that can happen to anyone—and does happen to me, especially in a blog post. We are all bears of very little brain, and none of us as smart individually as we are smart collectively, especially in that for of thinking that is manipulating systems of symbols.

More serious are the other two flaws. One models the behavior one wants to see students adopt. (1) Choosing an appropriate model, and (2) performing an analysis with a complete model are both very important things to, well, model.
Larry reaches more or less the same assessment about Mankiw’s choosing the wrong and an incomplete model—and then piles on still more complications:

…As a guide to the effects of the Trump administration’s tax cut, I do not think it is very helpful…. A cut in the corporate tax rate… in the presence of expensing… has very little impact on the incentive to invest…. The United States is not a small open economy…. A big cut in the corporate rate does not happen in isolation as a break for new investment… monopoly profits… other ways… benefit[ing] shareholders without encouraging investment… increases in other taxes or enlarged deficits… capital moves out of the noncorporate sector…

And I should also note Larry wishing for the public sphere debate on tax policy he wants to see. One in which due attention is paid to the true authorities:

the highest quality assessment… has been provided by Jane Gravelle,… of the Congressional Research Service. It looks at all the literature… recognizes that the issues are complex… does not start with a point of view… provides little support for claims that corporate rate cuts will raise revenue, help the middle class or spur rapid wage growth…

One in which all recognize the win-win importance of building up technocratic gatekeepers like CBO, GAO, CRS, and TPC, not tearing them down:

The inadequacy of their analyses illustrate why well-resourced, team-based institutions with a strong culture of attention to detail like the Congressional Budget Office, the GAO, the Joint Tax Committee Staff or the Tax Policy Center are so important…

One in which CEA Chairs regard themselves primarily as custodians of the intellectual quality of the public discourse rather than regarding themselves primarily as servants of their political masters:

I served with 7 CEA chairs — Martin Feldstein, Laura Tyson, Joe Stiglitz, Janet L. Yellen, Martin Baily, Christy Romer and Austan Goolsbee… all of them fighting with political figures… insist[ing] that CEA analysis had to be… respected and validated by outside economists… refus[ing] to cheerlead for Administration policies at the expense of their professional credibility. I cannot imagine any of them releasing an estimate as far from the professional mainstream as $4000 to $9000 wage increase from a corporate rate cut claim. Chairman Hassett should for the sake of his own credibility, that of the Administration he serves and the institution he leads, back off.

I started with Mill citing Cicero on philosophy. Let me end by citing Cicero on politics: how the problem with his ally Marcus Porcius Cato was that Cato acted as though he was living in the Republic of Plato rather than the Sewer of Romulus. At this stage I would be happy with the Sewer of Romulus. I would like to see some pushback from the right: people saying that, just as Kevin Hassett two decades went way too far with his claims that (a) the equity premium return was disappearing and that (b) that disappearance would carry the Dow to 36000 by 2004, Kevin Hassett has gone way too far with his claims of a 4000-9000 dollar/year average wage gain.

I am not holding my breath.

Must- and Should-Reads: October 23, 2017


Interesting Reads:

Ricardo’s Big Idea, and Its Vicissitudes

Ricardo’s Big Idea, and Its Vicissitudes

INET Edinburgh Comparative Advantage Panel

https://www.icloud.com/keynote/0QMFGpAUFCjqhdfLULfDbLE4g

Ricardo believes in labor value prices because capital flows to put people to work wherever those things can be made with the fewest workers. This poses a problem for Ricardo: The LTV tells him that capitalist production should take place according to absolute advantage, with those living in countries with no absolute advantage left in subsistence agriculture.

The doctrine of comparative advantage is Ricardo’s way out. For him, the LTV holds within countries. Countries’ overall price levels relative to each other rise and fall as a result of specie flows until trade balances. And what is left is international commodity price differentials that follow comparative advantage. Merchants profit from these differentials, and their demand induces specialization.
Thus Ricardo reconciles his belief in the LTV with his belief in Hume’s “On the Balance of Trade“ and with the fact that capitalist production is not confined to the industry-places with the absolute advantage. His doctrine reconciles his conflicting theoretical commitments with the reality he sees, as best he can.

By now, note that we are far away from the idea that “comparative advantage” justifies the claim that free trade is for the best in the best of all possible worlds. There are a large number of holes in that argument:

  • Optimal tariffs.
  • The fact of un- and underemployment.
  • Externalities as sources of economic growth, in any of the “extent of the market”, “economies of scale”, “variety”, “learning-by-doing”, “communities of engineering practice”, “focus of inventive activity”, or any of its other flavors.
  • Internal misdistribution means that the greatest profit is at best orthogonal to the “greatest good of the greatest number” that policy should seek.

Given these holes, the true arguments for free trade have always been a level or two deeper than “comparative advantage”: that optimal care of equilibrium is unstable; that other policy tools than trade restrictions resolve unemployment in ways that are not beggar-thy-neighbor; that countries lack the administrative competence to successfully execute manufacturing export-based industrial policies; that trade restrictions are uniquely vulnerable to rent seeking by the rich; and so forth.

The only hole for which nothing can be done is the internal misdistribution hole. Hence the late 19th C. “social Darwinist” redefinition of the social welfare function as not the greatest good of the greatest number but as the evolutionary advance of the “fittest“—that is, richest—humans.

Hence “comparative advantage” takes the form of an exoteric teaching: an ironclad mathematical demonstration that provides a reason for believing political-economic doctrines that are in fact truly justified by more complex and sophisticated arguments. And, I must say, arguments that are more debatable and dubious than a mathematical demonstration that via free trade Portugal sells the labor of 80 men for the products of the labor of 90 while England sells the labor of 100 men for the products of the labor of 110.

But even if you buy all the esoteric arguments that underpin the exoteric use of comparative advantage on the level of national political economy, there still is the question of the global wealth distribution. Stipulate that the Arrow-Debreu-Mackenzie machine generates a Pareto-optimal result. Stipulate that every Pareto-optimal allocation maximizes some social welfare function. What social welfare function does the Arrow-Debreu-Mackenzie machine maximize.

It maximizes the social welfare function with Negishi weights. When individual utilities are weighted before they are added, each individual’s is waited by the inverse of their marginal utility of wealth. If the typical individual utility function has curvature that corresponds to a relative risk aversion of one, then Negishi weights are proportional to each individual’s wealth. For a relative risk aversion of three, Negishi weights are proportional to the cube of each individual’s wealth.

“Comparative advantage” is the market economy on the international scale. And the market economy is a collective human device for satisfying the wants of the well-off. And the well-off are those who control scarce resources useful in producing things for which the rich have a serious Jones.

Thank you.

2017-10-22 :: 673 words


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Must-Read: Paul Krugman: Some Misleading Geometry on Corporate Taxes (Wonkish)

Must-Read:

  • Rule 1: Paul Krugman is right.
  • Rule 2: If you think Paul Krugman is wrong, consult Rule 1:

Paul Krugman: Some Misleading Geometry on Corporate Taxes (Wonkish): “There’s a fairly simple geometric way to see where the optimistic view that cutting corporate taxes is great for wages comes from…

…[Then] it becomes a lot easier to ask “What’s wrong with this picture?” (Answer: a lot)…. Envision a small open economy with a fixed labor force (because labor supply isn’t of the essence here) that can import from or export capital to the rest of the world…. Saving… also isn’t of the essence: the stock of capital, we’ll assume, changes only through capital inflows or outflows…. Let’s… assume… factors of production are paid their marginal products. Then we can represent the economy with Figure 1, which has the stock of capital [per worker] on the horizontal axis and the rate of return on capital on the vertical axis. The curve MPK is the marginal product of capital, diminishing in the quantity of capital because of the fixed labor force. The area under MPK – the integral of the marginal products of successive units of capital – is the economy’s real GDP, its total output….

Some Misleading Geometry on Corporate Taxes Wonkish The New York Times

The economy faces a given world rate of return r. However, the government imposes a profits tax at a rate t, so that to achieve a post-tax return r domestic capital must earn r*/(1-t)…. That… determines the size of the domestic capital stock…. In the initial equilibrium real output is a+b+d. Of this, d is the after-tax return to capital, b is profit taxes, and a – the rest – is wages.

Now imagine eliminating the profits tax (we can also do a small cut, but that’s harder and this is already sufficiently wonky). In equilibrium, the capital stock rises by ∆K, and… [GNP] to a+b+c+d… (e is returns to foreign capital)…. Profit taxes disappear: that’s a revenue loss of b. But wages rise to a+b+c, a gain of b+c….

What’s wrong with this picture?…. Four reasons…. First, a lot of what we tax with the corporate profits tax is… monopoly profits and other kinds of rents. There is no reason to believe that these rents would be bid down by capital inflows…. Second, capital mobility is far from perfect. Third, the US isn’t a small open economy…. Finally… what we’re showing here is long-run equilibrium… [after] capital inflows take place as the counterpart of trade deficits, which in turn have to be created by a temporarily overvalued real exchange rate. And the kind of adjustment we’re talking about here would require moving a lot of capital, meaning very big trade deficits, meaning a strongly overvalued dollar, which would itself be a deterrent to capital inflows. So we’re talking about a slow process…. Long-run analysis is a very poor guide to the incidence of corporate taxes in any politically or policy-relevant time horizon…

Paul is, of course, 100% correct.


There is a footnote with respect to Mankiw to be written here…

Suppose that you cut the corporate tax rate in this model from its initial level t by an amount Δt. The reduction in revenue collected is then:

By contrast, Mankiw miscalculates the “static” reduction in revenue as simply:

That is where the factor 1/(1-t) that puzzles him—”dw/dx = 1/(1 – t). I must confess that I am amazed at how simply this turns out. In particular, I do not have much intuition for why, for example, the answer does not depend on the production function”—comes from.

And do note that Alan Auerbach is right when he writes:

this result… is a combination of (1) the standard result that in a small open economy labor bears 100% of a small capital income tax…

and wrong when he writes:

the burden of a tax increase exceeds revenue collection due to the first-order deadweight loss…

The burden of a tax increase exceeds revenue collection due to the first-order deadweight loss, but Mankiw is claiming that even for an infinitesimal change in the tax rate—for which the deadweight loss term is infinitesimal relative to the distribution term—the ratio of revenue lost to wages gained is 1/(1-t). And that is simply a miscalculation of what the revenue loss is.

Must-Read: Jason Furman: Wage Increases Under the Unified Framework

Should-Read: I find Jason Furman totally convincing here. Which raises the question: what are those he is criticizing thinking?

More distressing, perhaps, is Jason’s defensive “(warning: irrelevant nerdy thread)”. If economists’ models are worth anything at all, it is only because you take the time to understand them and do them right…

Jason Furman: Wage Increases Under the Unified Framework: Some talk lately of Ramsey models and their implications for wage increases under the Unified Framework (warning: irrelevant nerdy thread)…

…I love the Ramsey model as much as the next person (OK, not as much as Greg or @caseybmulligan) but it has major limitations for this q. Ramsey ignores: (1) transition (2) distribution, (3) financing, (4) Δ interest rate, (5) effective marginal rates & (6) supernormal returns.

TRANSITION: May take a long time to get to the new steady state level. Is relevant because direct changes are sooner, matter more in PV.

DISTRIBUTION. POTUS claim is middle-class better off. Stipulate Greg Mankiw’s toy example is right: $200b corp tax cut, $300b wage increase. The means wages +3% (or $2,000—already below CEA but nevermind). But implicit in model is lump sum financing of $1,600/household. A household making $50,000 and no capital ownership gets a $1,500 wage boost and a $1,600 tax increase—or $100 worse off. Broader point: in model growth comes from replacing distortionary taxes with lump sums. Can’t ignore when evaluating middle class impact. Other models CEA has been pointing to also assume lump sum/other financing—but somehow only TPC gets attacked for filling in details.

FINANCING. Of course the Unified Framework does not have the $1,600 per hh lump sum financing. So it doesn’t have the growth effect either. The Unified Framework has deficit financing. Over time this reduces National Income—through less investment or more foreign borrowing. See, eg, the Penn-Wharton Budget Model of the President’s earlier principles (they have not updated for new plan). You can get different results in different models, is sensitive to when/how financed, but generally cuts or reverses growth effect.

INTEREST RATES. The above assumed that the US is not a small open economy & interest rate not the invariant social rate of time preference. I am very comfortable with those assumptions. I suspect you are too. Enough said.

EFFECTIVE MARGINAL RATES. Much investment is already debt-financed. It faces an effective rate ~0%. Cutting corp rate from 35% to 20% would cut the Effective Marginal Tax Rate by ~5pp give or take a lot. This is one reason why full-scale dynamic analysis of rate cuts with Ramsey models are so much smaller than these toy examples would suggest. If you have expensing and no interest deduction then cutting statutory rates does not reduce the EMTR at all. I know, State taxes, possibility that avg rates affect lumpy location decisions, etc. It is complicated. Point is simple model overstates.

SUPERNORMAL RETURNS. The Ramsey model only has normal/competitive returns to capital. The real world also has supernormal returns/rents. The deleted Treasury study estimated that 63% of corp income is rents—and some evidence rents are rising as concentration grows. In theory cutting taxes on rents will lead to higher after-tax profit but not anything else (“you get what you get and you don’t get upset”). In practice, maybe some of the extra rents shared with workers in a bargaining model. But not much and likely higher-income workers.

CONCLUSION. A lot of ways to look at impact of corp cut on middle class. None of them show middle-class families WAY better off.

Part of the problem here is that Unified Framework is incomplete (legislation will also be incomplete by not specifying future financing). A full(er) specified plan will allow a more complete assessment of the growth/distn/welfare aspects of the plan together. I hope we have time for that complete assessment…

Should-Read: Tim Duy: Incoming Data Supportive of December rate Hike

Should-Read: Tim Duy: Incoming Data Supportive of December rate Hike: “If we ignore inflation, then nothing is really standing in the way of a rate hike in December…

…Of course, given that arguably the primary job of a central bank is to meet its definition of price stability, the Fed shouldn’t really ignore inflation. Policymakers, however, would counter that they are not ignoring inflation. They are simply favoring the inflation forecast over actual in ation. And they would further argue they have good cause – with the economy chugging along, it is only a matter of time before resource constraints become evident and price pressures rise. That’s their story, and they are sticking to it…

Should-Read: Sandy Black: U.S. pattern looks very different. Suggests institutions matter and potential role for policy

Should-Read: Sandy Black: U.S. pattern looks very different. Suggests institutions matter and potential role for policy: “New book including my work with @dwschanz on female labor force participation….

…Prime-age (25-54) female LFP improved a lot until 2000. Now declining, similar to that of men. By marital status/children: Upward patterns were different by category, but the steady decline post 2000 is similar across all groups. U.S. pattern looks very different from other developed countries. Suggests institutions matter and potential role for policy. Also interesting: diffs by education/cohort. Pattern for lower educ women (steady decline across cohorts) similar to what we see for men…

Sandy Black on Twitter dwschanz Prime age 25 54 female LFP improved a lot until 2000 Now declining similar to that of men https t co xGAK0TQljN

Must-Read: Martin Wolf: Zombie ideas about Brexit that refuse to die

Must-Read: Martin Wolf: Zombie ideas about Brexit that refuse to die: “As Mark Carney, governor of the Bank of England, has rightly noted, the initial impact of Brexit will be ‘deglobalisation’…

…not a “global Britain”.

This is self-evident…. Today’s intra-industrial trade, particularly within supply chains… [is not] the inter-industry trade of the 19th century…. In trade today both proximity and regulatory barriers matter. It will be impossible to offset the loss of favourable access to EU markets, which now take some 40 per cent of the UK’s exports. Even to start on this, the UK would have to reach favourable deals with the US, China and India, the actual and potential superpowers. In all such negotiations, the UK will be very much the weaker party. Talks would be brutal.

Yet another zombie is the idea that it will be possible to shift smoothly to WTO terms for trade with the EU…. The last zombie is the idea that those who deny the claims of the Brexiters are “traitors” or “saboteurs” working against “the will of the people”. This is despotism. In a liberal democracy, we are all entitled to our opinions and to seek to overturn what we consider grossly mistaken decisions. The saboteurs are those whose zombie ideas have brought the UK to a ruinous break with its neighbours and natural partners. It is our right to argue this. And we will.