Foreign direct investment and spillovers : gradualism may be better

In contrast to the standard literature, we show that the presence of spillovers may justify temporarily restricting the inflow of foreign direct investment. Our argument is based on two stylized features of spillovers: first, technology transfers --- and subsequent spillovers --- are limited by the economy's absorptive capacity; and second, spillovers take time to materialize. By letting capital in more gradually, initial investment has the time to create spillovers --- and upgrade the economy's absorptive capacity --- before further investment occurs. This allows subsequent capital inflows to benefit from greater technology transfers. As a result, the economy converges to a steady state with a superior technology and a greater capital stock.We acknowledge financial support from the European Union Directorate General XII (project SERD-1999-000102) and of the Comunidad de Madrid (project 06/0186/2002

Reparametrization-Invariant Effective Action in Field-Antifield Formalism

We introduce classical and quantum antifields in the reparametrization-invariant effective action, and derive a deformed classical master equation.Comment: 14 pages, LaTeX. v2: Further observations, Added one appendix. v3: Version submitted to IJMPA. v4: Version published in IJMP

Path Integral Formulation with Deformed Antibracket

We propose how to incorporate the Leites-Shchepochkina-Konstein-Tyutin deformed antibracket into the quantum field-antifield formalism.Comment: 13 pages, LaTeX. v2: Added references. To appear in Phys. Lett.

Odd Scalar Curvature in Field-Antifield Formalism

We consider the possibility of adding a Grassmann-odd function \nu to the odd Laplacian. Requiring the total \Delta operator to be nilpotent leads to a differential condition for \nu, which is integrable. It turns out that the odd function \nu is not an independent geometric object, but is instead completely specified by the antisymplectic structure E and the density \rho. The main impact of introducing the \nu term is that it makes compatibility relations between E and \rho obsolete. We give a geometric interpretation of \nu as (minus 1/8 times) the odd scalar curvature of an arbitrary antisymplectic, torsion-free and \rho-compatible connection. We show that the total \Delta operator is a \rho-dressed version of Khudaverdian's \Delta_E operator, which takes semidensities to semidensities. We also show that the construction generalizes to the situation where \rho is replaced by a non-flat line bundle connection F. This generalization is implemented by breaking the nilpotency of \Delta with an arbitrary Grassmann-even second-order operator source.Comment: 23 pages, LaTeX. v2: More material added. v3: Reference added. v4: Grant number added. v5: Minor changes. v6: Stylistic change

Moving Moduli, Calabi-Yau Phase Transitions and Massless BPS Configurations in Type II Superstrings

In this paper we discuss compactifications of type II superstrings where the moduli of the internal Calabi-Yau space vary over four-dimensional space time. The corresponding solutions of four-dimensional N=2 supergravity are given by charged, extremal BPS black hole configurations with non-constant scalar field values. In particular we investigate the behaviour of our solutions near those points in the Calabi-Yau moduli space where some internal cycles collapse and topology change (flop transitions, conifold transitions) can take place. The singular loci in the internal space are related to special points in the uncompactified space. The phase transition can happen either at spatial infinity (for positive charges) or on spheres (with at least one negative charge). The corresponding BPS configuration has zero ADM mass and can be regarded as a domain wall that separates topologically different vacua of the theory.Comment: 14 pages, LaTeX, one figure, typos correcte