ABC (ATP-binding cassette) transporters are arguably the most important family of ATP-driven transporters in biology. Despite considerable effort and advances in determining the structures and physiology of these transporters, their fundamental molecular mechanisms remain elusive and highly controversial. How does ATP hydrolysis by ABC transporters drive their transport function? Part of the pr...

This article presents a model of international trade under monopolistic competition. In the increasing returns sector firms face fixed, in addition to variable, trade costs, and both exporters and non-exporters may coexist. Exporters benefit from access to large foreign markets, thus a small country has a higher share of exporting firms than a large one. In contrast to standard models, the incr...

Maximum residue levels (MRLs) regulations in plant products can create unnecessary trade barriers on one hand and enhance demand via risk mitigation or quality assurance on the other. We stipulate a generalized gravity equation model to disentangle the effects of MRLs on the import demand and foreign exporters’ supply. Applying the framework to the MRLs on pesticides imposed by high-income OECD...

This paper examines why credit constraints for domestic and exporting firms arise in a setting where banks do not observe firms’ productivities. To maintain incentive-compatibility, banks lend below the amount needed for first-best production. The longer time needed for export shipments induces a tighter credit constraint on exporters than on purely domestic firms, even in the exporters’ home m...

Recent theoretical models postulate that only the most productive …rms become exporters due to the existence of costs of exporting. Empirical evidence does suggest that exporters are on average more productive than their domestic counterparts. Using a Ukrainian manufacturing dataset I …nd that performance of exporters in Ukraine is heterogeneous across sectors and that the productivity distribu...

The use of Web for export marketing normally enables firms to leapfrog the conventional stages by removing a number of barriers associated with exporting. This study investigates the impact of Web presence on the perception of export barriers among Tirupur knitwear apparel exporters, Indian bricks and mortar manufacturing small firms. A mail survey was conducted among 950 active exporters with ...