Route planning is usually carried out to achieve a single objective such as to minimize transport cost, distance traveled or travel time. This article explores an approach to multi-objective route planning using a genetic algorithm (GA) and geographical information system (GIS) approach. The...

Large-scale studies of genetic variation may be helpful for understanding the genetic control mechanisms of viral infection and, ultimately, predicting and eliminating infectious disease outbreaks. We propose a new statistical model for detecting specific DNA sequence variants that are...

This paper presents theory and evidence from highly disaggregated Chinese data that tariff reductions induce a country's producers to upgrade the quality of the goods that they export. The paper first documents two stylized facts regarding the effect of trade liberalization on export prices and...

This paper presents theory and evidence from highly disaggregated Chinese data that tariff reductions induce exporters to upgrade product quality. The paper documents two stylized facts and develops a simple analytic framework to predict that import tariff reductions induce an incumbent...

This paper presents theory and evidence on firms' import responses to exchange rate fluctuations using disaggregated Chinese imports data. The paper develops a heterogeneous-firm trade model that predicts import responses at both extensive and intensive margins as well as the more profound...

This paper presents theory and evidence from Chinese firm-product data that, given firm productivity, trade liberalization increases product markups. This finding calls for a reconsideration of the well-established imports-as-market-discipline hypothesis. This paper further verifies underlying...

This paper presents theory and evidence that tighter credit constrains force firms to produce lower quality. The paper develops a quality sorting model that predicts that tighter credit constraints faced by a firm reduce its optimal prices due to its choice of lower-quality products. Conversely,...

This paper examines the relationship between the credit constraints faced by a firm and the unit value prices of its exports. The paper modifies Arkolakis’s (2010) model of trade with heterogeneous firms by introducing endogenous quality and credit constraints. The model predicts that tighter...

This paper explores the effects of distance as well as subnational and national borders on international and intranational knowledge spillovers through patent citations across the 39 most patent-cited countries and 319 metropolitan statistical areas (MSAs) within the U.S. In contrast to previous...