Computer simulation and design of a three degree-of-freedom shoulder module

An in-depth kinematic analysis of a three degree of freedom fully-parallel robotic shoulder module is presented. The major goal of the analysis is to determine appropriate link dimensions which will provide a maximized workspace along with desirable input to output velocity and torque amplification. First order kinematic influence coefficients which describe the output velocity properties in terms of actuator motions provide a means to determine suitable geometric dimensions for the device. Through the use of computer simulation, optimal or near optimal link dimensions based on predetermined design criteria are provided for two different structural designs of the mechanism. The first uses three rotational inputs to control the output motion. The second design involves the use of four inputs, actuating any three inputs for a given position of the output link. Alternative actuator placements are examined to determine the most effective approach to control the output motion

A Re-Examination of Exchange Rate Exposure

Finance theory suggests that changes in exchange rates should have little influence on asset prices in a world with integrated capital markets. Indeed, the existing literature examining the relationship between international stock prices and exchange rates finds little evidence of systematic exchange rate exposure. We argue in this paper that the absence of evidence may be due to restrictions imposed on the sample of data and the empirical specifications used in previous studies. We study a broad sample of firms in eight countries over an eighteen-year period. We find that firm-level and industry-level share values are significantly influenced by exchange rates. Further, we do not find evidence that exchange rate exposure is falling (or becoming less statistically significant) over time. Our results suggest that significant firm, industry and country-specific differences remain even as financial markets become more and more "integrated".

International Borrowing and Macroeconomic Performance in Argentina

This paper provides an overview of the major economic events in Argentina from the adoption of the convertibility plan in 1991 to the collapse of the exchange rate regime in 2001. We focus on the relationship between the credibility of the currency board and capital flows, and the inescapable link between fiscal and monetary policy. Argentina inadvertently entered into a vicious circle with financial markets -- one in which it felt compelled to raise the exit costs from the currency board in order to maintain the regime%u2019s credibility. As exit costs mounted, financial markets became increasingly concerned about the dire implications of a devaluation, which in turn, compelled the government to raise exit costs further. In the late 1990s, when Argentina went into recession, it required some sort of stimulus -- either a loosening of monetary policy (i.e. a devaluation) or fiscal stimulus. But either way spelled disaster. The added pressure of capital outflow, first by international investors and then the withdrawal of deposits from the Argentine banking system, eventually tipped the scales.

A Re-Examination of Exchange Rate Exposure

Finance theory suggests that changes in exchange rates should have little influence on asset prices in a world that has become increasingly with integrated capital markets. Indeed, the existing literature examining the relationship between international stock prices and exchange rates finds little evidence of systematic exchange rate exposure. We argue in this paper that the absence of evidence may be due to restrictions imposed on the sample of data and the empirical specifications used in previous studies. We study a broad sample of firms in eight countries over an eighteen-year period. We find that firm-level and industry-level share values are significantly influenced by exchange rates. Further, we do not find evidence that exchange rate exposure is falling (or becoming less statistically significant) over time. Our results suggest that significant firm, industry and country-specific differences remain even as financial markets become more and more 'integrated'.

Winners and Losers of Tax Competition in the European Union

This paper quantifies the macroeconomic effects of capital income tax competition in the European Union using a two-country neoclassical dynamic general equilibrium model. This model incorporates three key externalities of tax competition: the relative price externality, the wealth distribution externality and the fiscal solvency externality. We consider tax strategies limited to the class of time-invariant taxes and allow governments to issue debt to smooth the tax burden. The analysis starts from a pre-tax-competition equilibrium calibrated to represent the United Kingdom and Continental Europe (France, Germany and Italy) using data from the early 1980s, just before the European integration of financial markets. When labor taxes adjust to maintain fiscal solvency, competition does not trigger a “race to the bottom” in capital taxes. The UK makes a large welfare gain and cuts its capital tax. Continental Europe increases both labor and capital taxes and suffers a large welfare loss. These results are consistent with evidence showing that over the last two decades the UK lowered its capital tax, while Continental Europe increased both capital and labor taxes. When consumption taxes adjust to maintain fiscal solvency, there is a “race to the bottom” in capital taxes but both the UK and Continental Europe are better off than in the pre-tax-competition equilibrium. The gains from coordination in all of these experiments are trivial.

Trade and Exposure

Are firms that engage in trade more vulnerable to exchange rate risk? In this paper we examine the relationship between exchange rate movements, firm value and trade. Our empirical work tests whether exchange rate exposure can be explained by variables that proxy for the level of international activity, firm size, industry affiliation and country affiliation. The results suggest that while a significant fraction of firms in these countries is exposed to exchange rate movements, there is little evidence of a systematic link between exposure and trade. Indeed, what little evidence there is of a link suggests that firms that engage in greater trade exhibit lower degrees of exposure. This may reflect the fact that those firms most engaged in trade are also the most aware of exchange rate risk, and therefore are the most likely to hedge their exposure.

Multinationals and the Gains from International Diversification

One possible explanation for home bias is that investors may obtain indirect international diversification benefits by investing in multinational firms rather than by investing directly in foreign markets. This paper employs mean-variance spanning tests to examine the diversification potential of multinational firms and foreign market indices for investors domiciled in Canada, France, Germany, Italy, Japan, the United Kingdom and the United States. We find that in most countries and most time periods, the portfolio of domestic stocks spans the risk and return opportunities of a portfolio that includes domestic and multinational stocks. However, there is weak evidence that U.S. multinationals provided global diversification benefits in the full 1984-92 sample and in the post-1987 subsample. We also find that the addition of foreign market indices to a domestic portfolio - inclusive of multinationals - provides diversification benefits. The economic importance of the shift of the portfolio frontier - measured as the utility gain from diversification - varies considerably from market to market and often reflects the benefits of large short positions in certain markets.

Trade and Exposure

Are firms that engage in trade more vulnerable to exchange rate risk? Or, put another way, that exchange rate movements will influence firm asset value through the trade channel. In this paper we examine the relationship between exchange rate movements, firm value and trade. Our empirical work tests whether exchange rate exposure can be explained by variables that proxy for the level of international activity, firm size, industry affiliation and country affiliation. The results suggest that while a significant fraction of firms in these countries is exposed to exchange rate movements, there is little evidence of a systematic link between exposure and trade. Indeed, what little evidence there is of a link suggests that firms that engage in greater trade exhibit lower degrees of exposure. This may reflect the fact that those firms most engaged in trade are also the most aware of exchange rate risk, and therefore are the most likely to hedge their exposure.

A Quantitative Analysis of Tax Competition v. Tax Coordination under Perfect Capital Mobility

Theory predicts that strategically-determined tax rates induce negative externalities across countries in relative prices, the wealth distribution and tax revenue. This paper studies the interaction of these externalities in a dynamic, general equilibrium environment and its effects on quantitative outcomes of tax competition in one-shot games over capital income taxes between two governments that set time-invariant taxes and issue debt. Strategic payoffs correspond to welfare gains net of the cost of transitional dynamics in a standard neoclassical two-country model with exogenous balanced growth. The model is calibrated to European data for the early 1980s starting from a benchmark with symmetric countries. When countries compete over capital taxes adjusting labor taxes to maintain fiscal solvency, the Nash equilibrium replicates calibrated taxes, suggesting that European taxes can be the outcome of Nash competition. When consumption taxes are adjusted to maintain fiscal solvency, competition triggers a “race to the bottom” in capital taxes but this outcome is welfare-improving relative to calibrated taxes. Sensitivity analysis shows that competition can produce a “race to the top” in capital taxes and that the United Kingdom can benefit from tax competition with Continental Europe. Surprisingly, the gains from coordination in all of these experiments are small.