Technological Spillovers and Patterns of Growth with Sector-Specific R&D

This paper studies a two-sector model of endogenous technical change in which expansion of each production sector is associated with sector-specific R&D investment. It is shown that the pattern of growth is sensitive to the specification of intersectoral technological spillover as well as to the preference structure. If technological spillovers and preferences of consumers are represented by CES functional forms, the balanced-growth equilibrium may not exhibit a well-behaved saddlepoint property: it is possible that the balanced-growth path is locally indeterminate or unstable. In addition, a slight modification of technological spillover effects easily yields multiple balanced-growth paths. In contrast, Cobb-Douglas specifications present a unique and determinate balanced-growth path.R&D based growth, two-sector economy, technological spillover

A Variety-Expansion Model of Growth with External Habit Formation

This paper introduces external habit formation into one of the basic models of endogenous growth in which continuing expansion of product variety sustains long-term growth. We assume that households consume a range of final goods and they set a benchmark level of consumption for each good. The benchmark consumption is determined by external habit formation so that there are commodity-specific external effects. Each good is produced by a monopolistically competitive firm and the firmfs optimal pricing decision exploits the fact that consumersf demand is subject to the external habit formation. Given those settings, we show that the introduction of consumption externalities may affect the balanced-growth characterization, transitional dynamics as well as policy impacts in fundamental manners.consumption externalities, habit formation, monopolistic competition, R&Dbased growth model

A two-country dynamic model of international trade and endogenous growth: multiple balanced growth paths and stability

We formulate a two-country endogenous growth model which explain joint determination of long-run trade patterns and world growth rates. After providing the existence and local stability of the continuum of balanced growth paths, we show that main standard trade propositions hold under some modifications and that, subject to certain conditions concerning social and private rankings of factory intensities between production sectors, the higher is the growth rate, the smaller is the volume of international trade among balanced growth paths in the continuum.

Consumption Structure and the Pattern of Economic Growth

This paper studies the relationship between consumption structure and economic growth by constructing a two-sector variety expanding model. We classify the goods into two groups based on difference in the elasticity of substitution, and consider how the change of consumption structure affects economic growth. We consider the change as shifts in demand from the goods having higher elasticity (more competitive) to the other (less competitive) goods. As a result, we find that the growth rate is U-shaped

Nutrition and Depressive Symptoms in Community-dwelling Elderly Persons in Japan

A cross-sectional study was conducted to evaluate the association between dietary intake and depressivesymptoms in community-dwelling elderly persons. Five-hundred elderly persons aged 65 to 75 years were randomly selected from the population of O city in Okayama Prefecture, Japan. Among 401 respondents (response rate, 80.0%), data from 279 (133 males, 146 females) who completed the questionnaire concerning dietary intake and depressive state were analyzed using logistic regression. Each of 17 dietary intakes was classified into tertiles:high intake, moderate intake, and low intake. The Center for Epidemiology Studies Depression scale (CES-D) was used. Among males, the observed odds ratios (the 95% confidence intervals) for the depressive state were 0.36 (95% CI:0.13-0.98) in the highest tertile of carotene intake, 0.33 (95% CI:0.12-0.93) in the highest tertile of vitamin C intake, 0.29 (95% CI:0.10-0.85) in the highest tertile of carbohydrate intake, and 0.33 (95% CI:0.12-0.92) in the medium tertile of vitamin E intake. Among females, similar results were observed, but these results were not statistically significant. The results suggested that carbohydrate, carotene, and vitaminC intakes are associated with lowering depressive symptoms among elderly persons dwelling in communities in Japan.</p

Comparison of the Frequency of Functional SH3 Domains with Different Limited Sets of Amino Acids Using mRNA Display

Although modern proteins consist of 20 different amino acids, it has been proposed that primordial proteins consisted of a small set of amino acids, and additional amino acids have gradually been recruited into the genetic code. This hypothesis has recently been supported by comparative genome sequence analysis, but no direct experimental approach has been reported. Here, we utilized a novel experimental approach to test a hypothesis that native-like globular proteins might be easily simplified by a set of putative primitive amino acids with retention of its structure and function than by a set of putative new amino acids. We performed in vitro selection of a functional SH3 domain as a model from partially randomized libraries with different sets of amino acids using mRNA display. Consequently, a library rich in putative primitive amino acids included a larger number of functional SH3 sequences than a library rich in putative new amino acids. Further, the functional SH3 sequences were enriched from the primitive library slightly earlier than from a randomized library with the full set of amino acids, while the function and structure of the selected SH3 proteins with the primitive alphabet were comparable with those from the 20 amino acid alphabet. Application of this approach to various combinations of codons in protein sequences may be useful not only for clarifying the precise order of the amino acid expansion in the early stages of protein evolution but also for efficiently creating novel functional proteins in the laboratory

Technological Spillovers and Patterns of Growth with Sector-Specific R&D

This paper studies a two-sector model of endogenous technical change in which expansion of each production sector is associated with sector-specific R&D investment. It is shown that the pattern of growth is sensitive to the specification of intersectoral technological spillover as well as to the preference structure. If technological spillovers and preferences of consumers are represented by CES functional forms, the balanced-growth equilibrium may not exhibit a well-behaved saddlepoint property: it is possible that the balanced-growth path is locally indeterminate or unstable. In addition, a slight modification of technological spillover effects easily yields multiple balanced-growth paths. In contrast, Cobb-Douglas specifications present a unique and determinate balanced-growth path

The Effect of Lobbying in an Economy with Firm Heterogeneity and Unemployment : Searching for an Optimal Tariff Policy

本稿では、生産性が異質な企業と失業が存在する経済において、ロビー活動が厚生にどのような影響を及ぼすかを検討する。このため、Melitz (2003) を基礎として、企業のロビー活動と失業を明示的に示したモデルを構築する。ロビー活動は、経済全体の雇用と賃金に影響を与え、そのどちらの効果が大きいかによって、厚生に与える影響が異なることが明らかになった。このモデルを用いて、ロビー活動が関税率に与える影響を明らかにし、また、その結果、厚生がどのように変化するのかについて明らかにすることが残された課題である