Private Savings in Transition Economies: Are There Terms of Trade Shocks?

Economic agents in the transition economies are subject to tight credit constraints, which are more pronounced during bad state of nature. Thus, adverse shocks to commodity prices in the world market can force them to reduce savings by a larger amount than they would otherwise have. Empirical analysis using a dynamic panel model and data from 21 transition economies confirm that most of the determinants of savings identified in the literature also apply to the transition economies. The transitory component in the terms of trade have a larger positive impact than the permanent component. This reflects the lack of access to foreign borrowing. Although the impact of terms of trade shocks is found to be asymmetric, the magnitude of the impact appears to be small. The results are robust for alternative estimators, determinants and country groupings

Statin use after acute myocardial infarction by patient complexity: Are the rates right?

Reprinted with permission of the publisher.Background: Guidelines suggest statin use after acute myocardial infarction (AMI) should be close to universal in patients without safety concerns yet rates are much lower than recommended, decline with patient complexity, and display substantial geographic variation. Trial exclusions have resulted in little evidence to guide statin prescribing for complex patients. Objective: Assess the benefits and risks associated with higher rates of statin use after AMI by baseline patient complexity. Research Design: Sample includes Medicare fee-for-service patients with AMIs in 2008-2009. Instrumental variable estimators using variation in local area prescribing patterns by statin-intensity as instruments were used to assess the association of higher statin prescribing rates by statin-intensity on 1-year survival, adverse events, and cost by patient complexity. Results: Providers appear to have individualized statin use across patients based on potential risks. Higher statin rates for non-complex AMI patients were associated with increased survival rates with little added adverse event risk. Higher statin rates for complex AMI patients were associated with tradeoffs between higher survival rates and higher rates of adverse events. Conclusions: Higher rates of statin use for non-complex AMI patients are associated with outcome rate changes similar to existing evidence. For the complex patients in our study, who were least represented in existing trials, higher statin-use rates were associated with survival gains and higher adverse event risks not previously documented. Policy interventions promoting higher statin-use rates for complex patients may need to be re-evaluated taking careful consideration of these tradeoffs.This project was supported by an Agency for Healthcare Research and Quality grant (1R21HS019574-01) under the American Recovery and Reinvestment Act of 2009

Vulnerability of Microfinance to Strategic Default and Covariate Shocks: Evidence from Pakistan

This paper investigates the repayment behavior of microfinance borrowers in Pakistan using a unique dataset of about 45,000 installments/repayments covering 2,945 microfinance borrower households over the period 1998-2007. In early 2005, the microfinance institution for these borrowers adopted a new system with strict enforcement of punishment against repayment delays/defaults. This reform led to a healthy situation with almost zero default rates, overcoming the previous problem of frequent defaults. We hypothesize that strategic default under the joint liability mechanism--if one group member is hit by a negative shock and faces difficulty in repayment, the other members who are able to repay may decide to default as well, instead of helping the unlucky member--was encouraged by weak enforcement of dynamic incentives and responsible for the pre-reform failure. As evidence for this interpretation, we show that a borrower’s delay in installment repayment was correlated with other group members’ repayment delays, beyond the level explained by possible correlation of project failures due to locally covariate shocks during the pre-reform period. The post-reform period is divided into two sub-periods by an earthquake in October 2005. Analysis of repayment behavior in the post-reform period yields the results that suggest that (1) the relative success under the new system was because of the suppression of strategic behavior among group members, thereby allowing joint liability schemes to function as individual lending schemes de facto and (2) the earthquake only marginally affected the new system in terms of repayment delays.group lending, joint liability, contingent renewal, strategic default, covariate shocks

A Review of the Literature on Early Warning Systems for Banking Crises

This paper presents a review of alternative methodologies for early detection of banking distress. The methodologies proposed are aimed to the early identification of financial distress for countries without an important recent history of bank failure, but facing an unstable international environment. We evaluate several indicators and methodologies to measure financial distress such as qualitative indicators, the signal extraction approach, limited dependent estimation and finally duration models.

Patients' inability to perform a preoperative cardiopulmonary exercise test or demonstrate an anaerobic threshold is associated with inferior outcomes after major colorectal surgery.

BACKGROUND: Surgical patients with poor functional capacity, determined by oxygen consumption at anaerobic threshold (AT) during cardiopulmonary exercise testing (CPET), experience longer hospital stays and worse short- and medium-term survival. However, previous studies excluded patients who were unable to perform a CPET or who failed to demonstrate an AT. We hypothesized that such patients are at risk of inferior outcomes after elective surgery. METHODS: All patients undergoing major colorectal surgery attempted CPET to assist in the planning of care. Patients were stratified by their test results into Fit (AT ≥ 11.0 ml O2 kg(-1) min(-1)), Unfit (AT < 11.0 ml O2 kg(-1) min(-1)), or Unable to CPET groups (failed to pedal or demonstrate an AT). For each group, we determined hospital stay and mortality. RESULTS: Between March 2009 and April 2010, 269 consecutive patients were screened, and proceeded to bowel resection. Median hospital stay was 8 days (IQR 5.1-13.4) and there were 44 deaths (16%) at 2 yr; 26 (9.7%) patients were categorized as Unable to CPET, 69 (25.7%) Unfit and 174 (64.7%) Fit. There were statistically significant differences between the three groups in hospital stay [median (IQR) 14.0 (10.5-23.8) vs 9.9 (5.5-15) vs 7.1 (4.9-10.8) days, P < 0.01] and mortality at 2 yr [11/26 (42%) vs 14/69 (20%) vs 19/174 (11%), respectively (P < 0.01)] although the differences between Unable and Unfit were not statistically different. CONCLUSIONS: Patients' inability to perform CPET is associated with inferior outcomes after major colorectal surgery. Future studies evaluating CPET in risk assessment for major surgery should report outcomes for this subgroup

Training deep neural density estimators to identify mechanistic models of neural dynamics

Mechanistic modeling in neuroscience aims to explain observed phenomena in terms of underlying causes. However, determining which model parameters agree with complex and stochastic neural data presents a significant challenge. We address this challenge with a machine learning tool which uses deep neural density estimators-- trained using model simulations-- to carry out Bayesian inference and retrieve the full space of parameters compatible with raw data or selected data features. Our method is scalable in parameters and data features, and can rapidly analyze new data after initial training. We demonstrate the power and flexibility of our approach on receptive fields, ion channels, and Hodgkin-Huxley models. We also characterize the space of circuit configurations giving rise to rhythmic activity in the crustacean stomatogastric ganglion, and use these results to derive hypotheses for underlying compensation mechanisms. Our approach will help close the gap between data-driven and theory-driven models of neural dynamics

Nonlinear Elastic Material Property Estimation of Lower Extremity Residual Limb Tissues

The interface stresses between the residual limb and prosthetic socket have been studied to investigate prosthetic fit. Finite-element models of the residual limb-prosthetic socket interface facilitate investigation of the mechanical interface and may serve as a potential tool for future prosthetic socket design. However, the success of such residual limb models to date has been limited, in large part due to inadequate material formulations used to approximate the mechanical behavior of residual limb soft tissues. Nonlinear finite-element analysis was used to simulate force-displacement data obtained during in vivo rate-controlled (1, 5, and 10 mm/s) cyclic indentation of the residual limb soft tissues of seven individuals with transtibial amputation. The finite-element models facilitated determination of an appropriate set of nonlinear elastic material coefficients for bulk soft tissue at discrete clinically relevant test locations. Axisymmetric finite-element models of the residual limb bulk soft tissue in the vicinity of the test location, the socket wall and the indentor tip were developed incorporating contact analysis, large displacement, and large strain, and the James-Green-Simpson nonlinear elastic material formulation. Model dimensions were based on medical imaging studies of the residual limbs. The material coefficients were selected such that the normalized sum of square error (NSSE) between the experimental and finite-element model indentor tip reaction force was minimized. A total of 95% of the experimental data were simulated using the James-Green-Simpson material formulation with an NSSE less than 5%. The respective James-Green-Simpson material coefficients varied with subject, test location, and indentation rate. Therefore, these coefficients cannot be readily extrapolated to other sites or individuals, or to the same site and individual some time after testing

Experimental study of the compression behavior of mask image projection based on stereolithography manufactured parts

The article presents the results of a series of compression tests on samples manufactured by means of the mask image projection based on stereolithography additive manufacturing technique (MIP-SL). Recent studies demonstrate the orthotropic nature of the MIP-SL materials. A research is initiated by the authors to attempt to predict the degree of anisotropy from the manufacturing parameters of the MIP-SL parts. The article focuses mainly on the development of the experimental compression tests of the first stage of the research. Special attention is paid to the four methods used to obtain the stress-strain curve of the material: strain gages, 2D Digital Image Correlation, extensometer measurements and crosshead displacement measurements. The article shows the advantages and limitations of each method. Finally, the anisotropic behaviour is verified and a testing procedure is set to obtain the constitutive parameters of the MIP-SL tested materialsPeer ReviewedPostprint (published version

Equilibrium Exchange Rates in Transition Economies: Taking Stock of the Issues

In this paper we present an overview of a number of issues relating to the equilibrium exchange rates of transition economies of the former soviet bloc. In particular, we present a critical overview of the various methods available for calculating equilibrium exchange rates and discuss how useful they are likely to be for the transition economies. Amongst our findings is the result that the trend appreciation usually observed for the exchange rates of these economies is affected by factors other than the usual Balassa-Samuelson effect, such as the behaviour of the real exchange rate of the open sector and regulated prices. We then consider three main sources of uncertainty relating to the implementation of an equilibrium exchange rate model, namely: differences in the theoretical underpinnings; differences in the econometric estimation techniques; and differences relating to the time series and cross-sectional dimensions of the data. The ensuing three-dimensional space of real misalignments is probably a useful tool in determining the direction of a possible misalignment rather than its precise size.http://deepblue.lib.umich.edu/bitstream/2027.42/40179/3/wp793.pd

Vulnerability of Microfinance to Strategic Default and Covariate Shocks:Evidence from Pakistan

This paper investigates the repayment behavior of microfinance borrowers in Pakistan using a unique dataset of about 45,000 installments/repayments covering 2,945 microfinance borrower households over the period 1998-2007. In early 2005, the microfinance institution for these borrowers adopted a new system with strict enforcement of punishment against repayment delays/defaults. This reform led to a healthy situation with almost zero default rates, overcoming the previous problem of frequent defaults. We hypothesize that strategic default under the joint liability mechanism-if one group member is hit by a negative shock and faces difficulty in repayment, the other members who are able to repay may decide to default as well, instead of helping the unlucky member-was encouraged by weak enforcement of dynamic incentives and responsible for the pre-reform failure. As evidence for this interpretation, we show that a borrower’s delay in installment repayment was correlated with other group members’ repayment delays, beyond the level explained by possible correlation of project failures due to locally covariate shocks during the pre-reform period. The post-reform period is divided into two sub-periods by an earthquake in October 2005. Analysis of repayment behavior in the post-reform period yields the results that suggest that (1) the relative success under the new system was because of the suppression of strategic behavior among group members, thereby allowing joint liability schemes to function as individual lending schemes de facto and (2) the earthquake only marginally affected the new system in terms of repayment delays.group lending, joint liability, contingent renewal, strategic default, covariate shocks