Dual Polyhedra, Mirror Symmetry and Landau-Ginzburg Orbifolds

New geometrical features of the Landau-Ginzburg orbifolds are presented, for models with a typical type of superpotential. We show the one-to-one correspondence between some of the $(a,c)$ states with $U(1)$ charges $(-1,1)$ and the integral points on the dual polyhedra, which are useful tools for the construction of mirror manifolds. Relying on toric geometry, these states are shown to correspond to the $(1,1)$ forms coming from blowing-up processes. In terms of the above identification, it can be checked that the monomial-divisor mirror map for Landau-Ginzburg orbifolds, proposed by the author, is equivalent to that mirror map for Calabi-Yau manifolds obtained by the mathematicians.Comment: 8 pages, Late

On the Poincare polynomials for Landau-Ginzburg Orbifolds

We construct the Poincare polynomials for Landau-Ginzburg orbifolds with projection operators.Using them we show that special types of dualities including Poincare duality are realized under certain conditions. When Calabi-Yau interpretation exists, two simple formulae for Hodge numbers $h^{2,1}$ and $h^{1,1}$ are obtained.Comment: 10pages,Late

Political economy of labor provisions in free trade agreements

This paper examines the effects of the inclusion of labor provisions in free trade agreements (FTAs) on the external tariffs imposed on non-member countries and the political viability of FTAs within a political economy model in which oligopolistic industry may make political contributions on import tariffs against non-member countries. Labor provisions encourage external tariff reductions by party countries with low labor standards, while weakening the external tariff reduction effect for the party countries for which labor standards are sufficiently high so that the provisions are non-binding. Labor provisions also influence the political viability of FTAs. When an FTA has a labor provision, its political viability will increase in counties even with the highest labor standards

Do electricity supply constraints matter for comparative advantage? : a neoclassical approach

This paper examines the extent to which electricity supply constraints could affect sectoral specialization. For this purpose, an empirical trade model is estimated from 1990-2008 panel data on 15 OECD countries and 12 manufacturing sectors. We find that along with Ricardian technological differences and Heckscher-Ohlin factor-endowment differences, productivity-adjusted electricity capacity drives sectoral specialization in several sectors. Among them, electrical equipment, transport equipment, machinery, chemicals, and paper products will see lower output shares as a result of decreases in productivity-adjusted electricity capacity. Furthermore, our dynamic panel estimation reveals that the effects of Ricardian technological differences dominate in the short-run, and factor endowment differences and productivity-adjusted electricity capacity tend to have a significant effect in only the long-run

Product disposal : a market competition perspective

This paper examines the effect of competition among firms on their decisions about the pre-committed production (sales capacities), sales quantities, and product disposal in a duopoly model with demand uncertainty. A complete set of parameter configurations with which one of the following three cases emerges is identified: (i) neither capacity expansion nor product disposal occurring regardless of demand realization; (ii) only capacity expansion occurring when high demand is realized; and (iii) only product disposal occurring when low demand is realized. The flexibility in capacity constraints reduces the likelihood of product disposal. Duopolistic competition increases the likelihood that either capacity expansion or product disposal occurs. In addition, duopolistic competition leads to either higher or lower disposal intensities (product disposal per output) depending on the relative size of demand variability to production costs

Firm Heterogeneity and FDI with Matching Frictions

Firm-level data often show different modes of market access by firms with the same productivity levels, which is a mere knife-edge case in the basic firm heterogeneity model. This paper examines the foreign direct investment decisions of individual firms with a simple framework where firms and managers have to make matches for production. We find that predicted distributions of FDI firms are much more akin to real data than those suggested by the basic firm heterogeneity model and that sorting by firms' productivities becomes less sharp when either matching frictions increase or trade costs decline. Furthermore, matching frictions hurt production efficiency more for productive FDI firms than for less productive FDI firms.

Tariff reductions and labor demand elasticities : evidence from Chinese firm-level data

International production fragmentation has been a global trend for decades, becoming especially important in Asia where the manufacturing process is fragmented into stages and dispersed around the region. This paper examines the effects of input and output tariff reductions on labor demand elasticities at the firm level. For this purpose, we consider a simple heterogenous firm model in which firms are allowed to export their products and to use imported intermediate inputs. The model predicts that only productive firms can use imported intermediate inputs (outsourcing) and tend to have larger constant-output labor demand elasticities. Input tariff reductions would lower the factor shares of labor for these productive firms and raise conditional labor demand elasticities further. We test these empirical predictions, constructing Chinese firm-level panel data over the 2000--2006 period. Controlling for potential tariff endogeneity by instruments, our empirical studies generally support these predictions

Temporary jobs and globalization

Deregulation of the use of temporary workers in 2004 (the Worker Dispatching Act of 2004) has been regarded as an important reason for the recent rise of temporary workers in Japan. However, the shift from permanent to temporary workers began long before. This paper empirically explores links between the shift from permanent to temporary workers in the Japanese manufacturing sector and economic globalization, using industry-level data. We find that outsourcing is positively correlated with the replacement of permanent workers with temporary workers in domestic production. In addition, we find that industries losing world share of value added tend to decrease the employment of permanent workers. Industries with higher exports or imports are aggressive in using temporary workers, which suggests the role of temporary workers as an employment buffer