というNBER論文が上がっているungated版)。原題は「Reviving the Salter-Swan Small Open Economy Model」で、著者はコロンビア大のStephanie Schmitt-GrohéとMartín Uribe。

This paper provides microfoundations to the Salter-Swan policy framework, a graphical apparatus designed to ascertain the exchange-rate and fiscal stance of a policymaker with internal and external economic targets. The environment is an infinite-horizon small open economy producing tradable and nontradable goods that takes world prices and world interest rates as given and is populated by optimizing households and firms. The economy is subject to terms-of-trade and interest-rate shocks. The internal target of the government is the unemployment rate and the external target is the current account. Downward nominal wage rigidity and financial frictions serve as the rationale for meaningful policy intervention.


This paper provides microfoundations to the Salter-Swan policy framework. The Salter-Swan policy framework is a graphical apparatus for policy analysis in small open economies. In this apparatus, the targets of the policy maker are the internal and the external balance of the country. Internal balance means that the economy achieves full employment and price stability. External balance means that the country runs neither excessive current account deficits nor large current account surpluses. The instruments available to the policymaker are the exchange rate and fiscal policy.
The theoretical framework underlying the Salter-Swan policy theory is the tradable and nontradable goods model (also known as the Australian or dependent economy model) in the tradition of Swan (1955), Meade (1956), Salter (1959), Corden (1960), and Dornbusch (1974). The key insight of the tradable and nontradable goods model is the distinction between adjustment in aggregate demand and adjustment in its composition, the so called expenditure switch, when the economy is buffeted by exogenous aggregate disturbances, and the pivotal role played by the relative price of nontradables in facilitating the expenditure switch.
The following example illustrates the adjustment mechanism in the tradable and nontradable goods model: Suppose the country interest rate premium increases. This generates a contraction in domestic absorption as households and firms substitute future for current
spending. Given the relative price of nontradables in terms of tradables (the real exchange rate), the demand for tradables and nontradables falls. The increased gap between tradable output and tradable absorption can be exported. However, the increased gap between supply and demand of nontradables cannot be exported by definition. Thus, market clearing in the nontradable sector requires a decline in the relative price of nontradables. The fall in the relative price of nontradables causes a re-composition of aggregate expenditure away from tradables and toward nontradables and a re-composition of aggregate output in the opposite direction.
In the adjustment mechanism invoked by the tradable and nontradable goods model, the terms of trade (the relative price of exportables in terms of importables) plays no role. In fact, the model assumes that this variable is exogenous. Indeed, in the traditional international trade literature, this is the definition of a small open economy, one that can view the terms of trade as exogenous because it is too small to have any monopoly power. The insight that in a small open economy macroeconomic adjustment does not materialize through changes in the terms of trade represented a fundamental departure from the established view at the time of the creation of the Salter-Swan framework.


  • サルター=スワンモデル
    • 2つの目的(マクロ経済活動と経常収支)に対し2つの政策ツール(名目為替相場と政府支出)
    • 政府支出が完全に非生産的の場合でも有用(古典的ケインジアンの伝統)
  • 最近のモデル
    • 1つの目的(家計の生涯厚生の最大化)に対し1つの政策ツール(名目為替相場
    • 政府支出が完全に非生産的なら常にゼロにすることが最適となる
    • 政府支出が生産的な場合(効用関数に入る、もしくは企業の生産技術の効率要因となる、など)でも、経常収支とは結びつかないので、その循環特性は、本稿でミクロ的基礎付けを与えたサルター=スワンモデルとは違うものとなる



というNBER論文をスティグリッツらが上げている。原題は「Towards a Dynamic Disequilibrium Theory with Randomness」で、著者はMartin M. Guzman(コロンビア大)、Joseph E. Stiglitz(同)。

Most macroeconomic crises, such as the 2008 Global Financial Crisis, are associated with endogenous large changes in beliefs and understandings about the workings of the economy. Such downturns and crises are not consistent with the standard paradigm of a well-functioning competitive economy, and macroeconomic equilibrium models based on that paradigm have failed to predict the possibility of those downturns, to explain them, or even to design appropriate policy responses. The framework assumes there are no macroeconomic inconsistencies—all plans are realized, all budget constraints honored.
In this paper, we present a dynamic disequilibrium theory with randomness that is based on the premise that a better way to understand deep downturns is to think of the economy experiencing a constant evolution, marked by uncertainty, in which there is continual learning about the economic system. Our framework explains why macroeconomic inconsistencies may arise and investigates their consequences. We explain why decentralized market forces may be disequilibrating. We identify the crucial departures from the Arrow-Debreu assumptions and those underlying DSGE models, emphasizing the limitations in the assumption of equilibrium and the absence of a coherent theory of how it is attained, the incompleteness of markets and the non-stationarity of the stochastic processes describing the economy. We analyze the policy implications of this alternative theory, which typically differ markedly from those of the standard model: In particular, the consequences for the effectiveness of different monetary and fiscal policies, and the eventual need of debt restructuring policies to restore macroeconomic consistency.


というNBER論文が上がっている。原題は「Optimal Lockdown in a Commuting Network」で、著者はPablo Fajgelbaum(UCLA)、Amit Khandelwal(コロンビア大)、Wookun Kim(南メソジスト大)、Cristiano Mantovani(ポンペウ・ファブラ大)、Edouard Schaal(同)。

We study optimal dynamic lockdowns against Covid-19 within a commuting network. Our framework integrates canonical spatial epidemiology and trade models, and is applied to cities with varying initial viral spread: Seoul, Daegu and NYC-Metro. Spatial lockdowns achieve substantially smaller income losses than uniform lockdowns, and are not easily approximated by simple centrality-based rules. In NYM and Daegu—with large initial shocks—the optimal lockdown restricts inflows to central districts before gradual relaxation, while in Seoul it imposes low temporal but large spatial variation. Actual commuting responses were too weak in central locations in Daegu and NYM, and too strong across Seoul.


Our first results show that the optimal lockdowns are not easily approximated by simple centrality-based rules. Instead, they depend on the geography of commute flows, real income, and the initial viral spread. In NYM and Daegu - where the virus initially spread very quickly - locations with high virus-diffusion potential are subject to a strict initial lockdown, eliminating 40% to 80% of pre-pandemic inflows depending on the city and location, which is relaxed over 3 to 6 months. In NYM many other locations are imposed an early lockdown, but only the top-3 central locations (Manhattan, Brooklyn, and Bronx) are still closed after 100 days, and remain so in expectation that a vaccine arrives. In contrast, in Seoul - where the initial spread of Covid-19 was much smaller - the planner initially locks down only a few locations of relatively high centrality. As the virus spreads, the lockdown intensifies and retains considerable spatial variation across locations.


「Pandemic Shocks and Fiscal-Monetary Policies in the Eurozone: COVID-19 Dominance During January - June 2020」というNBER論文が上がっている。著者はYothin Jinjarak(ヴィクトリア大学ウェリントン)、Rashad Ahmed(南カリフォルニア大)、Sameer Nair-Desai(同)、Weining Xin(同)、Joshua Aizenman(同)。

This case study compares the importance of prevailing market factors against that of COVID-19 dynamics and policy responses in explaining the evolution of Eurozone (EZ) sovereign spreads during the first half of 2020. Focusing on daily Eurozone CDS spreads, we adopt a multi-stage econometric approach. First, we estimate a multi-factor model for changes in EZ CDS spreads over the pre-COVID-19 period of January 2014 through June 2019. Then, we apply a synthetic control-type procedure to extrapolate model-implied changes in the CDS from July 2019 through June 2020. We find that the factor model does very well in tracing the realized sovereign spreads over the rest of 2019, but breaks down during the pandemic – diverging substantially in March 2020. In the second stage, focusing specifically on the 2020 period, we find that the March 2020 divergence is well accounted for by COVID-specific risks and associated policies. In particular, mortality outcomes and policy announcements, rather than traditional determinants like fiscal space and systematic risk, drove CDS adjustment over this period. Daily CDS spread widening ceased almost immediately after the ECB announced the PEPP, but the divergence between actual and model-implied changes persisted. This divergence can be traced back to the fact that fiscally secure EZ Core countries saw spreads widen further than implied – comparable to the widening of more fragile countries - as several of the Core countries were hit hard by COVID-19. Taken all together, this points to COVID-19 Dominance: The widening spreads during the pandemic induced by COVID-specific risks and fiscal responses has led to unconventional monetary policies that primarily aim to mitigate the short-run fear of the worst economic outcomes, temporarily pushing away concerns over fiscal risk.

*1:cf. ここ


というNBER論文が上がっている。原題は「Epidemics in the Neoclassical and New Keynesian Models」で、著者はMartin S. Eichenbaum(ノースウエスタン大)、Sergio Rebelo(同)、Mathias Trabandt(ベルリン自由大)。

We analyze the effects of an epidemic in three standard macroeconomic models. We find that the neoclassical model does not rationalize the positive comovement of consumption and investment observed in recessions associated with an epidemic. Introducing monopolistic competition into the neoclassical model remedies this shortcoming even when prices are completely flexible. Finally, sticky prices lead to a larger recession but do not fundamentally alter the predictions of the monopolistic competition model.


The intuition for our results is as follows. Consider first the neoclassical model. Suppose that people can become infected through consumption activities but not by working. Then, an epidemic leads to a large drop in consumption and a boom in investment. The latter boom reflects two forces: the household wants to consume more once the infection wanes and it wants to smooth hours worked over time. By building up the capital stock, it can accomplish both objectives.
Now suppose that people can become infected by working but not through consumption activities. Then, an epidemic leads to a small decline in consumption but a large fall in hours worked and output. There is also a large fall in investment because households smooth consumption in the face of a transitory fall in income.
In the calibrated version of the model, people can become infected through both consumption and working activities. We find that the shift in consumption demand dominates the shift in labor supply. So consumption falls but investment remains above its steady-state value throughout most of the epidemic.


In contrast, in the monopolistic competition model the shift in labor supply dominates the shift in consumption demand. So an epidemic generates a steep recession along with sharp declines in both consumption and investment. The shift in labor supply becomes more important because monopolistic competition reduces the real wage relative to the case of perfect competition. A lower wage means that the compensation to a worker for being exposed to the virus is lower. The household responds by reducing hours worked of nonimmune people by more than it does under perfect competition. As a result, consumption and investment comove positively.


Sticky prices increase the depth of the recession relative to the model with monopolistic competition and flexible prices. But the effect of sticky prices is relatively small. The intuition for this result is as follows. It is well known that nominal price rigidities exacerbate the effects of negative demand shifts. But they alleviate the impact of negative supply shifts. Since both shifts are operative during an epidemic, sticky prices do not, on net, have a strong effect on the response of output to an epidemic.

COVID-19と安定化政策は支出と雇用にどのように影響したか? 民間部門データに基づく新たなリアルタイム経済トラッカー

というNBER論文をここの注記で紹介したThe Opportunity Insightsチームが上げている。原題は「How Did COVID-19 and Stabilization Policies Affect Spending and Employment? A New Real-Time Economic Tracker Based on Private Sector Data」で、著者はRaj Chetty(ハーバード大)、John N. Friedman(ブラウン大)、Nathaniel Hendren(ハーバード大)、Michael Stepner(同)、およびThe Opportunity Insights Team。

We build a publicly available platform that tracks economic activity at a granular level in real time using anonymized data from private companies. We report daily statistics on consumer spending, business revenues, employment rates, and other key indicators disaggregated by county, industry, and income group. Using these data, we study the mechanisms through which COVID-19 affected the economy by analyzing heterogeneity in its impacts across geographic areas and income groups. We first show that high-income individuals reduced spending sharply in mid-March 2020, particularly in areas with high rates of COVID-19 infection and in sectors that require physical interaction. This reduction in spending greatly reduced the revenues of businesses that cater to high-income households in person, notably small businesses in affluent ZIP codes. These businesses laid off most of their low-income employees, leading to a surge in unemployment claims in affluent areas. Building on this diagnostic analysis, we use event study designs to estimate the causal effects of policies aimed at mitigating the adverse impacts of COVID. State-ordered reopenings of economies have little impact on local employment. Stimulus payments to low-income households increased consumer spending sharply, but had modest impacts on employment in the short run, perhaps because very little of the increased spending flowed to businesses most affected by the COVID-19 shock. Paycheck Protection Program loans have also had little impact on employment at small businesses. These results suggest that traditional macroeconomic tools – stimulating aggregate demand or providing liquidity to businesses – may have diminished capacity to restore employment when consumer spending is constrained by health concerns. During a pandemic, it may be more fruitful to mitigate economic hardship through social insurance. More broadly, this analysis illustrates how real-time economic tracking using private sector data can help rapidly identify the origins of economic crises and facilitate ongoing evaluation of policy impacts.


というNBER論文が上がっている。原題は「Misinformation During a Pandemic」で、著者はLeonardo Bursztyn(シカゴ大)、Aakaash Rao(ハーバード大)、Christopher P. Roth(ウォーリック大)、David H. Yanagizawa-Drott(チューリッヒ大)。

Examining the effects of misinformation is particularly important during a pandemic given the large externalities involved and the significant consequences of misinformed behavior for individuals' health and for the health care system as a whole. The two most widely-viewed cable news shows in the United States -- Hannity and Tucker Carlson Tonight, both on Fox News -- originally took very different stances on the risks associated with the novel coronavirus. While Hannity downplayed the threat during the initial period of the virus' spread in the United States, Tucker Carlson Tonight warned its viewers that the virus posed a serious threat from early February. In this paper, we show that differential exposure to these two shows affected behavior and downstream health outcomes.
We begin by validating differences in content with independent coding of shows' transcripts. Consistent with the differences in content, we present new survey evidence that Hannity's viewers changed behavior in response to the virus later than other Fox News viewers, while Carlson's viewers changed behavior earlier. Using both OLS regressions with a rich set of controls and different instrumental variable strategies exploiting variation in the timing of TV consumption, we then document that greater exposure to Hannity relative to Tucker Carlson Tonight increased the number of total cases and deaths in the initial stages of the coronavirus pandemic. We also show that a standard epidemiological model can, with reasonable parameter levels, match the approximate magnitude of our measured treatment effects. Finally, we also provide additional evidence that misinformation is an important mechanism driving the effects in the data. Our results indicate that the provision of misinformation on mass media can have significant societal consequences.