Diffusion of an Inhomogeneous Vortex Tangle

The spatial diffusion of an inhomogeneous vortex tangle is studied numerically with the vortex filament model. A localized initial tangle is prepared by applying a counterflow, and the tangle is allowed to diffuse freely after the counterflow is turned off. Comparison with the solution of a generalization of the Vinen equation that takes diffusion into account leads to a very small diffusion constant, as expected from simple theoretical considerations. The relevance of this result to recent experiments on the generation and decay of superfluid turbulence at very low temperatures is discussed.Comment: 2 pages, 2 figure

Location and organization choice of firms

We construct a two-region model of monopolistic competition with mobile entrepreneurs. Typical implicit assumption on increasing returns to scale sector is that firms can produce and sale only at one place. We explicitly introduce multi-plant case and examine location equilibrium with decreasing transpiration costs. The difference between single-plant and multi-plant firms lies in export-fixed cost and set-up fixed cost of multi-plant. We find that at certain transportation costs, firms change their organization type from multi-plant to single-plant and, with further decrease in transportation costs, firms concentrate in one region.Economic Integration, Organization of Production, Horizontal FDI, Export Fixed Cost, Transaction Cost

Views on Food Production: Towards a New Green Revolution

Farm Management,

Agglomeration and wage bargaining

This paper examines the role of trade union and the type of wage bargainings in economic geography model. In our setting, wage bargaining is held between immobile workers and mobile entrepreneurs who decide the location of their firm. It is shown that stronger trade unions in both regions would put a stronger pressure toward agglomeration of firms. This is due to the fact that the stronger bargaining power of trade union makes home market effect larger. Under core-periphery distribution of firms, this effect can act the role as anchorage of firms. Stronger trade unions in home region can keep the firms remain in their region. Moreover, we extend to several employment environments, which are the outside option of workers. We show that differences in bargaining structures and employment environments could affect the stability of symmetrically distributed firms, namely symmetry break point. We show that while unemployment rate acts as a centripetal force, not only the degree of bargaining power of trade union but also unemployment benefit can play as a centrifugal force. A key message of the paper is that generous unemployment benefit and higher trade union make the distribution of firms more uneven and sustainable.Labour market rigidity, Regional Unemployment, Location of firms, Anchorage effect of trade union