Trade Costs, Limited Enforcement and Risk Sharing: A Joint Test

This paper addresses the question of whether goods or asset market frictions are necessary to explain the failure of consumption risk sharing across countries. I present a multi-country DSGE model with Armington specialization. There are iceberg costs of shipping goods across countries. In asset markets, contracts are imperfectly enforceable. Both frictions separately limit the extent to which countries can pool risk. The model suggests a test for the presence of each of the two types of friction that can be implemented using data on bilateral imports. I implement this test using a sample of developed and developing countries. I find that both trade costs and asset market imperfections are necessary in order to explain the failure of perfect consumption risk sharing. However the null hypothesis of financial autarky is rejectedrisk sharing, trade costs, asset market frictions

Specialization, Factor Accumulation and Development

The Heckscher-Ohlin theory links specialization of production to relative factor endowments. Endowments are the result of accumulation in response to economic in-centives. Taking this into account allows us to reconcile wildly di¤erent predictions in the empirical literature about the e¤ect of capital accumulation on manufacturing output. We estimate the e¤ect of factor proportions on specialization in a cross-section of OECD countries. We show that using the estimation results alone, we cannot dis-tinguish between specialization driven by factor proportions, and specialization that is correlated with factor proportions for other reasons. But our results are consistent with evidence on sectoral factor intensities, which supports the H-O theory. Moreover, our model does a good job of predicting the substantial reallocation that takes place within manufacturing as countries grow. It explains 2/3 of the observed di¤erence in the pattern of specialization between the poorest and richest OECD countries.

Specialization, Factor Accumulation and Development

We estimate the effect of factor proportions on the pattern of manufacturing specialization in a cross-section of OECD countries, taking into account that factor accumulation responds to productivity. We show that the failure to control for productivity differences produces biased estimates. Our model explains 2/3 of the observed differences in the pattern of specialization between the poorest and richest OECD countries. However, because factor proportions and the pattern of specialization co-move in the development process, their strong empirical relationship is not sufficient to determine whether specialization is driven by factor proportions, or by other mechanisms also correlated with level of development.

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Trade, Interdependence and Exchange Rates

The empirical “gravity” equation is extremely successful in explaining bilateral trade. This paper shows how a multi-country model of specialization and costly trade (i.e. a microfounded gravity model) can be applied to explain empirical exchange rate puzzles. One such puzzle is the fact that nominal exchange rates are enormously volatile, but that this volatility does not appear to affect inflation. The gravity model is very successful in explaining this puzzle. In a sample of 25 OECD countries in the post- Bretton Woods period, the gravity prediction of inflation substantially outperforms the purchasing power parity prediction. The gravity prediction matches the volatility of actual inflation, and tracks its path closely. The superior performance of the gravity prediction is explained primarily by the fact that it takes account of the interaction of specialization with home bias. The stability of inflation in very open economies is explained in addition by the fact that the size of bilateral trade is negatively correlated with bilateral exchange rate volatility

Trade, Interdependence and Exchange Rates

The empirical “gravity” equation is extremely successful in explaining bilateral trade. This paper shows how a multi-country model of specialization and costly trade (i.e. a microfounded gravity model) can be applied to explain empirical exchange rate puzzles. One such puzzle is the fact that nominal exchange rates are enormously volatile, but that this volatility does not appear to affect inflation. The gravity model is very successful in explaining this puzzle. In a sample of 25 OECD countries in the post- Bretton Woods period, the gravity prediction of inflation substantially outperforms the purchasing power parity prediction. The gravity prediction matches the volatility of actual inflation, and tracks its path closely. The superior performance of the gravity prediction is explained primarily by the fact that it takes account of the interaction of specialization with home bias. The stability of inflation in very open economies is explained in addition by the fact that the size of bilateral trade is negatively correlated with bilateral exchange rate volatility

Trade Costs, Asset Market Frictions and Risk Sharing: A Joint Test

Why does international consumption risk sharing fail? I propose a new test that uses data on bilateral imports to identify whether both trade costs and asset market frictions are necessary to explain this failure. I implement the test using a sample of 73 developed and developing countries, 1970-2000. The null hypothesis of no trade costs is overwhelmingly rejected for both developed and developing countries. Two versions of the test give contrasting results on the role of asset market frictions. The baseline test does not reject the null hypothesis of frictionless asset markets within developed countries, though it does reject between developed and developing countries. A variant on the baseline test …nds that the marginal utility of wealth moves with current income for both developed and developing countries. But the sensitivity of the marginal utility of wealth to income in developed countries is 1/3 of what it is in developing countries, and is only marginally signi…cantly di¤erent from zero