Sustainability of the US current account deficit: An econometric analysis of the impact of capital inflow on domestic economy

The purpose of this paper is to estimate, by using the recent econometric techniques of unit root testing and Johansen-Juselius cointegration technique (1990), the impact of foreign capital inflow on the volume and efficiency of domestic investment in the United States during the period, 1973-1999. A battery of diagnostic tests is employed to check the validity and robustness of the estimated results. Evidence suggests that capital inflows have had a significant positive effect on the volume of US investment, but the effect on the efficiency of investment has been minimal. These findings imply that, while achieving current account balance is important, it is equally important to sustain and augment the beneficial impact of capital inflow by creating a more conducive investment climate. Given our limited ability to influence current account balance, this seems to be a more pragmatic policy option for dealing with the US current account imbalance.current account, capital inflow

Freight Rates and Productivity Gains in British Tramp Shipping 1869-1950

The standard source for pre-WWII global freight rate trends is the Isserlis British tramp shipping index. We think it is flawed, and that its sources offer vastly more information than the Isserlis aggregate contains. The new data confirm the precipitous decline in nominal freight rates before the World War I, but it also extends the series to the 1940s. Furthermore, our new series is linked to the post-World War II era (documented by David Hummels), so that we can be more precise about what has happened over the very long run. We also create route-specific deflators by using the prices of commodities transported. Previous scholars have deflated their nominal freight rate indices by a price index that includes tradables not carried on all routes and non-tradables not carried on any route. Our deflated indices offer a more effective measure of the contribution of declining freight rates to commodity-price convergence across trading regions. Using the pricedual method and new indices for factor prices, we then calculate total factor productivity growth pre-war and interwar for five global routes. Finally, we identify the sources of the total factor productivity growth.

An Intelligent Tutoring System for Teaching Grammar English Tenses

The evolution of Intelligent Tutoring System (ITS) is the result of the amount of research in the field of education and artificial intelligence in recent years. English is the third most common languages in the world and also is the internationally dominant in the telecommunications, science and trade, aviation, entertainment, radio and diplomatic language as most of the areas of work now taught in English. Therefore, the demand for learning English has increased. In this paper, we describe the design of an Intelligent Tutoring System for teaching English language grammar to help students learn English grammar easily and smoothly. The system provides all topics of English grammar and generates a series of questions automatically for each topic for the students to solve. The system adapts with all the individual differences of students and begins gradually with students from easier to harder level. The intelligent tutoring system was given to a group of students of all age groups to try it and to see the impact of the system on students. The results showed a good satisfaction of the students toward the system

Homological mirror symmetry for punctured spheres

We prove that the wrapped Fukaya category of a punctured sphere ($S^2$ with an arbitrary number of points removed) is equivalent to the triangulated category of singularities of a mirror Landau-Ginzburg model, proving one side of the homological mirror symmetry conjecture in this case. By investigating fractional gradings on these categories, we conclude that cyclic covers on the symplectic side are mirror to orbifold quotients of the Landau-Ginzburg model.Comment: 38 pages, 5 figures; v2: minor revisions (similar to published version