International Capital Mobility in Developing Countries vs. Industrial Countries: What do Saving-Investment Correlations Tell Us?

The finding of Feldstein and Horioka (1980) that countriesf investment rates are highly correlated with their national saving rates has by now been confirmed by many subsequent studies, even though their inference that international capital mobility nust be low has not been as widely accepted. This paper examines the statistical relationship between national saving and investment in a sample that includes not only 14 industrialized countries, but also 50 developing countries. The paper addresses some of the econometric critiques that have been aimed at the Feldstein-Horioka work. Contrary to what one would expect from consideration of capital mobility, the coefficient appears higher for industrialized countries than for developing countries, and higher after 1973 than before. Our interpretation of the saving-investment evidence is that the hypothesis of a high degree of substitutability for claims on physical capital located in different countries is not supported by the data. International substitutability for financial capital may be nigh, but this is a separate condition (which is properly tested by looking directly at rates of return). High international substitutability for bonds would imply high international substitutability for physical capital if capital were perfectly substitutable for bonds within each country, but there is no reason for this to hold, any more than there is for all goods to be perfect substitutes.

An Empirical Exploration of Exchange Rate Target-Zones

In the context of a flexible-price monetary exchange rate model and the assumption of uncovered interest parity, we obtain a measure of the fundamental determinant of exchange rates. Daily data for the European Monetary System are used to explore the importance of non-linearities in the relationship between the exchange rates and fundamentals. Many implications of existing "target-zone" exchange rate models are tested; little support is found for existing non-linear models of limited exchange rate flexibility.

Capital Mobility and Exchange Market Intervention in Developing Countries

This paper develops a new technique for measuring changes in the degree of capital mobility confronting a developing country that has restrictions on capital flows and official ceilings on domestic interest rates. Because such official controls rule out the use of traditional interest rate parity conditions to measure changes in the degree of capital mobility, the analysis first examines an intertemporal model of an open economy. This model describes the linkages between the cost of undertaking disguised capital flows, the current account, capital controls, domestic and external financial market conditions, and the authorities' foreign exchange market interventions. The model suggests a means of measuring changes in the cost of undertaking disguised capital flows, based on the past history of differentials between external interest rates (adjusted for exchange rate changes) and domestic ceiling interest rates, provided that the authorities' foreign exchange market activities are incorporated into the analysis. Parameter estimates for Korea, Mexico, and the Philippines indicate that the real cost of undertaking disguised capital flows declined on average by nearly 70 percent between the early 1970s and the late 1980s.

An optrode array for spatiotemporally precise large-scale optogenetic stimulation of deep cortical layers in non-human primates

Optogenetics has transformed studies of neural circuit function, but remains challenging to apply in large brains, such as those of non-human primates (NHPs). A major challenge is delivering intense, spatiotemporally precise, patterned photostimulation across large volumes in deep tissue. Such stimulation is critical, for example, to modulate selectively deep-layer corticocortical feedback projections. To address this unmet need, we have developed the Utah Optrode Array (UOA), a 10×10 glass needle waveguide array fabricated atop a novel opaque optical interposer then bonded to an electrically addressable μLED array. In vivo experiments with the UOA demonstrated large-scale, spatiotemporally precise, activation of deep circuits in monkey cortex. Specifically, the UOA permitted both focal (confined to single layers/columns), and widespread (multiple layers/columns) optogenetic activation of deep layer neurons, simply by varying the number of activated μLEDs and/or the irradiance. Thus, the UOA represents a powerful optoelectronic device for targeted manipulation of deep-layer circuits in NHP models.Competing Interest StatementThe authors have declared no competing interest

An optrode array for spatiotemporally-precise large-scale optogenetic stimulation of deep cortical layers in non-human primates

Optogenetics has transformed studies of neural circuit function, but remains challenging to apply to non-human primates (NHPs). A major challenge is delivering intense, spatiotemporally-precise, patterned photostimulation across large volumes in deep tissue. Such stimulation is critical, for example, to modulate selectively deep-layer corticocortical feedback circuits. To address this need, we have developed the Utah Optrode Array (UOA), a 10×10 glass needle waveguide array fabricated atop a novel opaque optical interposer, and bonded to an electrically addressable µLED array. In vivo experiments with the UOA demonstrated large-scale, spatiotemporally precise, activation of deep circuits in NHP cortex. Specifically, the UOA permitted both focal (confined to single layers/columns), and widespread (multiple layers/columns) optogenetic activation of deep layer neurons, as assessed with multi-channel laminar electrode arrays, simply by varying the number of activated µLEDs and/or the irradiance. Thus, the UOA represents a powerful optoelectronic device for targeted manipulation of deep-layer circuits in NHP models

Estimating Models of Financial Market Behaviour during Periods of Extensive Structural Reform: The Experience of Chile (Estimation de modèles du comportement du marché financier en périodes de réformes structurelles généralisées: l'expérience du Chili) (La estimación de modelos de comportamineto del mercado financiero durante períodos de reforma estructural amplia: La experiencia de Chile)

This paper examines the problems involved in estimating portfolio balance models of the behavior of financial markets during a period of extensive structural reforms. The model encompasses specifications of the portfolio behavior of banks and nonbanks (firms and households) regarding holdings of currency, demand deposits, time deposits, and bank loans. In addition, the analysis describes the determinants of bank loan and time deposit rates and the linkages between inflation, the balance of payments, interest rates, and financial aggregates. The model is estimated for a sample of monthly Chilean data from July 1965 to June 1980. The estimation results are also contrasted with those obtained in previous work on Argentina. /// L'auteur de la présente étude analyse les difficultés que présente l'estimation de modèles du comportement du marché financier -- axés sur l'équilibre des portefeuilles -- en périodes de réformes structurelles généralisées. Le modèle spécifie le comportement en matière de portefeuilles des banques et des agents non bancaires (entreprises et ménages) au niveau des avoirs en monnaie, des dépôts à vue, des dépôts à terme et des prêts bancaires. L'analyse comporte également une description des facteurs déterminants des taux servis sur les prêts bancaires et les dépôts à terme ainsi que des liens existant entre l'inflation, la balance des paiements, les taux d'intérêt et les agrégats financiers. Le modèle est estimé au moyen d'un échantillon de données mensuelles observées au Chili pendant la période allant de juillet 1965 à juin 1980. Enfin, l'auteur compare les résultats à ceux obtenus dans le cadre d'une étude effectuée antérieurement pour l'Argentine. /// En este estudio se abordan los problemas de la estimación de modelos de equilibrio de cartera del comportamiento de los mercados financieros durante un período de amplias reformas estructurales. El modelo incluye especificaciones del comportamiento de cartera de la banca y del sector no bancario (empresas y unidades familiares) en cuanto a las tenencias de moneda, depósitos a la vista, depósitos a plazo y préstamos bancarios. También se describen los factores determinantes de los tipos de interés de los préstamos bancarios y los depósitos a plazo, y los vínculos entre inflación, balanza de pagos, tipos de interés y agregados financieros. Se estima el modelo para una muestra de datos mensuales chilenos que abarca desde julio de 1965 hasta junio de 1980. Se comparan también los resultados de la estimación con los obtenidos en un trabajo anterior sobre Argentina.