Thermofield Dynamics of the Heterotic String - Physical Aspects of the Thermal Duality -

The thermofield dynamics of the D = 10 heterotic thermal string theory is described in proper reference to the thermal duality symmetry as well as the thermal stability of modular invariance in association with the global phase structure of the D = 10 heterotic thermal string ensemble.Comment: 8 pages, LaTeX, Minor correction

Thermal DD-Brane Boundary States from Green-Schwarz Superstrings

In this paper we thermalize the type II superstrings in the GS formulation by applying the TFD formalism. The thermal boundary conditions on the thermal Hilbert space are obtained from the BPS $D$-brane boundary conditions at zero temperature. We show that thermal boundary states can be obtained by thermalization from the BPS $D$-branes at zero temperature. These new states can be interpreted as thermal $D$-branes. Next, we discuss the supersymmetry breaking of the thermal string in the TFD approach. We identify the broken supersymmetry with the $\epsilon$-transformation while the $\eta$-transformation is preserved. Also, we compute the thermal partition function and the entropy of the thermal string.Comment: 23 pages, LATeX fil

Interest Rate Control Rules and Macroeconomic Stability in a Heterogeneous Two-Country Model

We analyze relations between several types of interest rate control rules and equilibrium determinacy using a two-country model featuring preference and production parameters that may differ between countries, in which two kinds of goods are tradable. Such heterogeneity may violate the Taylor principle, which implies that aggressive monetary policy is desirable to attain determinate equilibrium. We evaluate the forms of interest rate control needed to attain macroeconomic stability in consideration of the heterogeneity.heterogeneity; Taylor rule; open economy; equilibrium determinacy

Habit Formation, Interest-Rate Control and Equilibrium Determinacy

We examine macroeconomic stability of a monetary economy with habit formation in consumption. We assume that monetary authority controls the rate of nominal interest in response to inflation and output gap. We show that in the presence of habit persistence not only active but also passive monetary policy can generate equilibrium determinacy under empirically plausible values of the elasticity of intertemporal substitution in felicity.equilibrium determinacy, habit formation, Taylor rule, endogenous labor.

Growth and Distributional Effects of Inflation with Progressive Taxation

This paper examines the growth and income distribution effects of inflation in a growing economy with heterogeneous households and progressive income taxation. Assuming that the cash-in-advance constraint applies to investment as well as to consumption spending, we show that a higher growth of monetary supply yields a negative impact on growth and an ambiguous effect on income distribution. Numerical example with plausible parameter values, however, demonstrate that those long-run effects of money growth are rather small. In contrast, fiscal distortion caused by progressive taxation yield significant impacts on growth and distribution.Inflation, Progressive Income Tax, Growth, Income Distribution

Long-Run Impacts of Inflation Tax in the Presence of Multiple Capital Goods

This paper examines the long-run impact of inflation tax in the context of a generalized Ak growth model in which the production technology uses two types of capital stocks under a constant-returns-to-scale technology. We find that unless investment expenditure for each type of capital is subject to the same degree of cash-in-advance constraint, a change in the money growth rate affects the steady-state level of factor intensity. It is shown that if the balanced-growth path is uniquely given, we still have a negative longrun relationship between money growth and the growth rate of real income. However, due to the endogenous determination of the factor intensity, the negative relation between the velocity of money and the rate of inflation may not be established.