Effects of pre-hatching pCO2 on development and survival of zoea stages of Arctic spider crab Hyas araneus

Sensitivity of marine crustaceans to anthropogenic CO2 emissions and the associated acidification of the oceans may be less than that of other, especially lower, invertebrates. However, effects on critical transition phases or carry-over effects between life stages have not comprehensively been explored. Here we report the impact of elevated seawater PCO2 values (3100 µatm) on Hyas araneus during the last 2 weeks of their embryonic development (pre-hatching phase) and during development while in the consecutive zoea I and zoea II larval stages (post-hatching phase). We measured oxygen consumption, dry weight, developmental time and mortality in zoea I to assess changes in performance. Feeding rates and survival under starvation were investigated at different temperatures to detect differences in thermal sensitivities of zoea I and zoea II larvae depending on pre-hatch history. When embryos were pre-exposed to elevated PCO2 during maternal care, mortality increased about 60% under continued CO2 exposure during the zoea I phase. The larvae that moulted into zoea II, displayed a developmental delay by about 20 days compared to larvae exposed to control PCO2 during embryonic and zoeal phases. Elevated PCO2 caused a reduction in zoea I dry weight and feeding rates, while survival of the starved larvae was not affected by the seawater CO2 concentration. In conclusion, CO2 effects on egg masses under maternal care carried over to the first larval stages of crustaceans and reduced their survival and development to levels below those previously reported in studies exclusively focussing on acute PCO2 effects on the larval stages.

Economies of Transport Density and Industrial Agglomeration

This paper develops a model of a spatial economy in which interregional trade patterns and the structure of the transport network are determined endogenously as a result of the interaction between industrial location behavior and increasing returns in transportation, in particular, economies of transport density. The traditional models assume either the structure of the transport network or industrial location patterns, and hence, they are unable to explain the interdependence of the two. It is shown that economies of transport density can be the primary source of industrial localization.

Infrastructure (Rural Road) Development and Poverty Alleviation in Lao PDR

Rural road in Lao PDR defined as connecting road from village to main road, where it will lead them to market and access to other economic and social service facilities. However, due to mostly rural people accustom with subsistence farming, connecting road seems less important for rural people as their main farming produce is for own consumption rather than markets. After the introduction and implementation of New Economic Mechanism (NEM) since 1986, many rural villages have gradually developed and integrated into market system where people have significantly changed their livelihood with a better system. This progress has significantly contributed in improving income earning of people, better living standard and reduce poverty. The paper aims to illustrate the significant of rural road as connecting road from village to markets or a market access approach of farm produces. It also demonstrates through which approach, rural farmers/people could improve their income earning, develop their farming system, living standard and reduce poverty.

Introduction New Challenges in New Economic Geography

2009年度調査研究報告書

Chapter 1 Market Access and Intermediate Goods Trade

This paper examines a distinctive feature of intermediate goods trade which the traditional gravity equation fails to capture, i.e., intermediate goods trade is positively related not only to the importing country's demand for finished goods but also to its neighbors' demand for finished goods. We regress a gravity equation for finished goods trade in the first step. Then, introducing the importing country's access to the total demand for finished goods which is calculated by using the estimates in the first step, we regress our gravity equation for trade in intermediate goods. Our regression results confirm such a feature of intermediate goods trade. Using the results of the regression, we simulate how the rise of US consumers' demand for finished goods affects the total imports and exports of intermediate goods in each country.

Chapter 2 Equilibrium locations of upstream and downstream firms

This paper explores the interaction between upstream firms and downstream firms in a two-region general equilibrium model. In many countries, lower tariff rates are set for intermediate manufactured goods and higher tariff rates are set for final manufactured goods. The derived results imply that such settings of tariff rates tend to preserve a symmetric spread of upstream and downstream firms, and continuing tariff reduction may cause core-periphery structures. In the case in which the circular causality between upstream and downstream firms is focused as agglomeration forces, the present model is fully solved. Thus, we find that (1) the present model displays, at most, three interior steady states, (2) when the asymmetric steady-states exist, they are unstable and (3) location displays hysteresis when the transport costs of intermediate manufactured goods are sufficiently high.

Chapter 5 Product Differentiation versus Geographical Differentiation: Evidence from the Pork Processing Industry in China

This chapter attempts to identify whether product differentiation or geographical differentiation is the main source of profit for firms in developing economies by employing a simple idea from the recently developed method of empirical industrial organization. Theoretically, location choice and product choice have been considered as analogues in differentiation, but in the real world, which of these strategies is chosen will result in an immense difference in firm behavior and in the development process of the industry. Development of the technique of empirical industrial organization enabled us to identify market outcomes with endogeneity. A typical case is the market outcome with differentiation, where price or product choice is endogenously determined. Our original survey contains data on market location, differences in product types, and price. The results show that product differentiation rather than geographical differentiation mitigates pressure on price competition, but 70 per cent secures geographical monopoly.

Spatial spillovers from FDI agglomeration : evidence from the Yangtze River Delta in China

Foreign firms have clustered together in the Yangtze River Delta, and their impact on domestic firms is an important policy issue. This paper studies the spatial effect of FDI agglomeration on the regional productivity of domestic firms, using Chinese firm-level data. To identify local FDI spillovers, we estimate the causal impact of foreign firms on domestic firms in the same county and similar industries. We then estimate a spatial-autoregressive model to examine spatial spillovers from FDI clusters to other domestic firms in distant counties. Our results show that FDI agglomeration generates positive spillovers for domestic firms, which are stronger in nearby areas than in distant areas.

Search, matching, and self-organization of a marketplace

In many developing countries, clusters of small shops are the typical market-place. We investigate an economic model in which, between buyers and sellers in a marketplace, a circular causality including the search process produces agglomeration forces, given the initial location of the marketplace location exogenously in a linear city. We conclude that initial number of buyers and sellers is important in forming a large marketplace.

The location of manufacturing firms and imperfect information in transport market

It is well know that transport charges are not symmetric: fronthaul and backhaul costs on a route may differ, because they are affected by the distribution of economic acitivities. This paper develops a two-regional general equilibrium model in which transport costs are determined endogenously as a result of a search and matching process. It is shown that economies or diseconomies of transport density emerge, depending on the search costs of transport firms and the relative importance of the possibility of backhaul transportation. It is found that the symmetry of the distribution of economic activity may break owing to economies of transport density when the additional search costs are small enough.

Agglomeration and directional imbalance of freight rates : the role of density economies in the transport sector

This paper examines the conventional assumption that bilateral transport costs are symmetric. We develop an economic geography model with transport sector in which asymmetric freight rates can occur as a result of density economies. Comparing this to models without density economies, we show that agglomeration of economic activities is more likely to emerge and that multiple equilibria can emerge for some parameters. Then we show the change in its bifurcation and stability of equilibrium and conclude that economies of density in transport flows can act as an agglomeration force.

Industrial agglomeration in Costa Rica : a descriptive analysis

This paper investigates the current situation of industrial agglomeration in Costa Rica, utilizing firm-level panel data for the period 2008-2012. We calculated Location Quotient and Theil Index based on employment by industry and found that 14 cantons have the industrial agglomerations for 9 industries. The analysis is in line with the nature of specific industries, the development of areas of concentration around free zones, and the evolving participation of Costa Rica in GVCs.

Heterogeneous firms and cost sharing in China's marketplaces

This study extends Melitz's model with heterogeneous firms by introducing shared fixed costs in a marketplace. It aims to explain heterogeneous firms' choice between traditional marketplaces and modern distribution channels on the basis of their productivities. The results reveal that the co-existence of a traditional marketplace and modern distribution channels improves social welfare. In addition, a deregulation policy for firm entry outside a marketplace and accumulation of human capital are factors that contribute to improve the social welfare.

Does technological progress magnify regional disparities?

We study how technological progress in manufacturing and transportation to-gether with migration costs interact to shape the space-economy. Rising labor productivity in the manufacturing sector fosters the agglomeration of activities, whereas falling transport costs associated with technological and organizational in-novations fosters their dispersion. Since these two forces have been at work for a long time, the final outcome must depend on how drops in the costs of producing and trading goods interact with the various costs borne by migrants. Finally, when labor is heterogeneous, the most efficient workers of the less productive region are the first to move to the more productive region.

Development and Assessment of the Competence Creativity Applied to Technical Drawing

The results obtained after incorporating the competence “creativity” to the subject Technical Drawing of the first course of the Degree in Forestry, Technical University of Madrid, are presented in this study.At first, learning activities which could serve two functions at the same time -developing students’ creativity and developing other specific competences of the subject- were considered. Besides, changes in the assessment procedure were made and a method which analyzes two aspects of the assessment of the competence creativity was established. On the one hand, the products are evaluated by analyzing the outcomes obtained by students in the essays suggested and by establishing a parameter to assess the creativity expressed in those essays. On the other, an assessment of the student is directly carried out through a psychometric test which has been previously chosen by the team.Moreover, these results can be applied to similar or could be of general application