A Quantile Based Test of Protection for Sale Model

This paper proposes a new test of the Protection for Sale (PFS) model by Grossman and Helpman (1994). Unlike existing methods in the literature, our approach does not require any data on political organizations. We formally show that the PFS model provides the following prediction: In the quantile regression of the protection measure on the inverse import penetration ratio divided by the import demand elasticity, its coefficient should be positive at the quantile close to one. We examine this prediction using the data from Gawande and Bandyopadhyay (2000). The results do not provide any evidence favoring the PFS model.Quantile Regression, Protection for Sale, Political Economy

A Quantile-based Test of Protection for Sale Model

This paper proposes a new test of the Protection for Sale (PFS) model by Grossman and Helpman (1994). Unlike existing methods in the literature, our approach does not require any data on political organization. We use quantile and quantile IV regressions to do so using the data from Gawande and Bandyopadhyay (2000). Surprisingly, the results do not provide any evidence favoring the PFS model. We also explain why previous work may have inadvertently found support for it.protection for sale, lobbying, political economy, quantile regression

Is Protection Really for Sale? A Survey and Directions for Future Research

This paper critically and selectively surveys the literature on protection for sale and discusses directions for future research in this area. It suggests that the standard approach needs to be augmented to provide more compelling tests of this model.Common agency, Political economy, Protection for sale, Quotas, Non tariff barriers

Protection for Sale or Surge Protection?

This paper asks whether the results obtained from using the standard approach to testing the influential Grossman and Helpman "protection for sale" (PFS) model of political economy might arise from a simpler setting. A model of imports and quotas with protection occuring in response to import surges, but only for organized industries, is simulated and shown to provide parameter estimates consistent with the protection for sale framework. This suggests that the standard approach may be less of a test than previously thought.Common agency, Political economy, Protection for sale, Quotas, Non tariff barriers

A Quantile-based Test of Protection for Sale Model

This paper proposes a new test of the Protection for Sale (PFS) model by Grossman and Helpman (1994). Unlike existing methods in the literature, our approach does not require any data on political organization. We use quantile and quantile IV regressions to do so using the data from Gawande and Bandyopadhyay (2000). Surprisingly, the results do not provide any evidence favoring the PFS model. We also explain why previous work may have inadvertently found support for it.Protection for Sale, Lobbying, Political Economy, Quantile Regression

Protection for Sale or Surge Protection?

This paper asks whether the results obtained from using the standard approach to testing the influential Grossman and Helpman %u201Cprotection for sale (PFS)%u201D model of political economy might arise from a simpler setting. A model of imports and quotas with protection occurring in response to import surges, but only for organized industries, is simulated and shown to provide parameter estimates consistent with the protection for sale framework. This suggests that the standard approach may be less of a test than previously thought.

Is Protection Really for Sale? A Survey and Directions for Future Research

This paper critically and selectively surveys the literature on protection for sale and discusses directions for future research in this area. It suggests that the standard approach needs to be augmented to provide more compelling tests of this model.

A Quantile-based Test of Protection for Sale Model

This paper proposes a new test of the Protection for Sale (PFS) model by Grossman and Helpman (1994). Unlike existing methods in the literature, our approach does not require any data on political organizations. We formally show that the PFS model predicts that the quantile regression of the protection measure on the inverse import penetration ratio divided by the import demand elasticity, should yield a positive coefficient for quantiles close to one. We test this prediction using the data from Gawande and Bandyopadhyay (2000). The results do not provide any evidence favoring the PFS model.

Code Building Genetic Programming

In recent years the field of genetic programming has made significant advances towards automatic programming. Research and development of contemporary program synthesis methods, such as PushGP and Grammar Guided Genetic Programming, can produce programs that solve problems typically assigned in introductory academic settings. These problems focus on a narrow, predetermined set of simple data structures, basic control flow patterns, and primitive, non-overlapping data types (without, for example, inheritance or composite types). Few, if any, genetic programming methods for program synthesis have convincingly demonstrated the capability of synthesizing programs that use arbitrary data types, data structures, and specifications that are drawn from existing codebases. In this paper, we introduce Code Building Genetic Programming (CBGP) as a framework within which this can be done, by leveraging programming language features such as reflection and first-class specifications. CBGP produces a computational graph that can be executed or translated into source code of a host language. To demonstrate the novel capabilities of CBGP, we present results on new benchmarks that use non-primitive, polymorphic data types as well as some standard program synthesis benchmarks.Comment: Proceedings of the 2020 Genetic and Evolutionary Computation Conference, Genetic Programming Trac

Bicuspid aortic valves undergo excessive strain during opening: A simulation study

ObjectiveThe objective of this study was to examine the influence of the morphologic characteristics of the bicuspid aortic valve on its disease progression by comparing the motion, stress/strain distribution, and blood flow of normal and stenotic tricuspid valves using simulation models.MethodsBicuspid, stenotic tricuspid with commissural fusion or thickened leaflet, and normal aortic valves were modeled with internal blood flow. Blood flow and the motion of aortic valve leaflets were studied using fluid–structure interaction finite element analysis, and stress/strain (curvature) distributions were calculated during the cardiac cycle. To mimic disease progression, we modified the local thickness of the leaflet where the bending stress was above a threshold.ResultsTransvalvular pressure gradient was greater in the bicuspid valve compared with the stenotic tricuspid valve with a similar valvular area. The bending strain (curvature) increased in both stenotic tricuspid and bicuspid valves, but a greater increase was observed in the bicuspid valve, and this was concentrated on the midline of the fused leaflets. During disease progression analysis, severity of the stenosis increased only in the bicuspid aortic valve model in terms of valvular area and pressure gradient.ConclusionsThe characteristic morphology of the bicuspid valve creates excessive bending strain on the leaflets during ventricular ejection. Such mechanical stress may be responsible for the rapid progression of this disease