Human capital externalities, trade, and economic growth

Human capital, because of its special role in innovative activity and technological progress, has formed the bedrock of the new theories of endogenous growth. Human capital, however, not only serves as an engine of growth, but also as a productive input along with labor and physical capital. In this study, we distinguish between these two roles of human capital and find evidence of the importance of both. We also find that the relationship between growth and the external effects of human capital vary according to trade regime. When literacy rates are relatively high, open economies grow about 0.65 to 1.75 percentage points more than closed economies. Replaced by "Human capital, trade and economic growth"Economic development ; Human capital

Trade deficits: causes and consequences

According to conventional wisdom, trade balances reflect a country's competitive strength-the lower the trade deficit, the stronger the country's industries and the higher its rate of economic growth. In this article, David Gould and Roy Ruffin review the history of the conventional wisdom and empirically examine whether large overall trade deficits or bilateral trade imbalances are associated with lower rates of economic growth. They find that, once the fundamental determinants of growth have been accounted for, trade imbalances have little effect on rates of economic growth.Deficit financing ; Free trade

The theory and practice of free trade

David M. Gould, Roy J. Ruffin, and Graeme L. Woodbridge argue that free trade is supported both by economic principles and evidence from countries that have followed open market policies. The authors demonstrate that the countries whose markets are the most open have higher real output and economic growth. ; The authors show that many arguments for protection obscure the benefits countries derive from international trade. High-wage countries not only can compete with low-wage countries, they dominate the world economic stage. Trade deficits or surpluses are not inherently bad or good, but rather reflect a country's consumption and investment decisions over time. Moreover, there is no evidence to suggest that imports cause systematic unemployment or that exports create systematic employment. The authors explain why industrial policies and protection designed to promote particular industries usually backfire; trade policies usually reflect the lobbying efforts of the most vocal and powerful self-interest groups.Free trade

Income taxes as reciprocal tariffs

Tariff ; Taxation

Income taxes as reciprocal tariffs

This article shows the equivalence between tariffs on international trade and income taxation. Traditionally, income taxes have been seen as lowering society's output through the household's labor-leisure trade-off. Income taxes also reduce the degree to which individuals specialize in market activity, which is similar to the way countries respond to tariffs in international trade. Income taxes discourage individuals from specializing in activities that reflect their comparative advantage. In so doing, income taxes may have their most distorting effects, not by encouraging individuals to work less but by causing them to spend more time working at endeavors for which their talent is limited. Using a general model of interpersonal exchange, the authors demonstrate parallels between income taxes and tariffs. Over a range of income taxes, raising taxes can benefit large groups of similarly skilled individuals and hurt small groups. As in tariff theory, the costs of income taxes are small only if they succeed in raising revenue. Thus, it is very costly for an economy to be on the downward portion of its tax revenue (Laffer) curve. The more heterogeneous the society, the higher the income tax rate that will maximize tax revenues. By overlooking the effects of heterogeneity in the workforce and the potential for workers to flee to home production, policymakers may under- or overestimate the effects of income taxes on various sectors of the economy and tax with unintended consequences.Income tax ; Tariff ; Taxation

Inhibition of established collagen-induced arthritis with a tumour necrosis factor-α inhibitor expressed from a self-contained doxycycline regulated plasmid

Tumor necrosis factor (TNF)-α is produced by cells of the immune system and is a key mediator in immune and inflammatory reactions. Through interaction with widely expressed receptors (TNF receptor 1 and TNF receptor 2), TNF-α is able to orchestrate the expression of a range of downstream proinflammatory molecules. Over the past decade novel biologics that inhibit TNF-α have been developed as extremely effective treatments for rheumatoid arthritis. Structurally, these biologics are antibodies, or TNF receptors on an antibody backbone that bind TNF-α directly and are delivered to patients by repeated injection. Gene therapy offers an improved approach to delivering biologics as a single administration of their encoding genetic material. In the present study we demonstrate the therapeutic effect of a small molecular weight dimeric TNF receptor 2 (dTNFR) constitutively expressed from plasmid DNA, delivered intramuscularly with electroporation, after disease onset in a collagen-induced arthritis model. Regulated promoters that enable the production of a transgene to be controlled are more suited to the application of gene therapy in the clinic. Regulated expression of dTNFR from the plasmid pGTRTT was also therapeutic in the mouse collagen-induced arthritis model when the inducer doxycycline was also administered, whereas no therapeutic effect was observed in the absence of doxycycline. The therapeutic effect of dTNFR expressed from a constitutive or regulated plasmid was dependent on the degree of disease activity at the time of DNA injection. The observations of this study are considered with regard to the disease model, the magnitude of gene regulation, and the path to clinical application

Schwinger pair production of magnetic monopoles : Momentum distribution for heavy-ion collisions

Magnetic monopoles may be produced by the dual Schwinger effect in strong magnetic fields. Today, the strongest known magnetic fields in the Universe are produced fleetingly in heavy-ion collisions. We use the complex worldline instanton method to calculate the momentum distribution of magnetic monopoles produced in heavy-ion collisions, in an approximation that includes the effect of the magnetic field to all orders but neglects monopole self-interactions. The result saturates the preparation time-energy uncertainty principle, and yields a necessary ingredient for experimental monopole searches in heavy-ion collisions.Peer reviewe

Towards Schwinger production of magnetic monopoles in heavy-ion collisions

Magnetic monopoles may be produced by the Schwinger effect in the strong magnetic fields of peripheral heavy-ion collisions. We review the form of the electromagnetic fields in such collisions and calculate from first principles the cross section for monopole pair production. Using the worldline instanton method, we work to all orders in the magnetic charge, and hence are not hampered by the breakdown of perturbation theory. Our result depends on the spacetime inhomogeneity through a single dimensionless parameter, the Keldysh parameter, which is independent of collision energy for a given monopole mass. For realistic heavy-ion collisions, the computational cost of the calculation becomes prohibitive and the finite size of the monopoles needs to be taken into account, and therefore our current results are not applicable to them-we indicate methods of overcoming these limitations, to be addressed in further work. Nonetheless, our results show that the spacetime dependence enhances the production cross section and would therefore lead to stronger monopole mass bounds than in the constant-field case.Peer reviewe

Strategy for the reduction of total integrated fluid logistics to the Space Station Freedom

The use of an integrated environmental control and life support system (ECLSS) and secondary propulsion system (SRS) on the Space Station Freedom (SSF) has many potential advantages. Through the metabolism of food, the crew on-board the station will produce carbon dioxide as a waste gas and an excess of water in the form of urine and condensate. The processing of these waste fluids by the ECLSS could produce quantities of oxygen that would eliminate the need for cryogenic oxygen resupply and hydrogen, carbon dioxide, and/or methane that could be used with the addition of a resistojet system to provide a constant low thrust for station. This additional thrust would represent significant savings in required hydrazine resupply