This paper estimates the impact of the tsunami caused by the Great East Japan earthquake on land appraisals of various locations outside of directly damaged areas. The focus is on locations that are ...expected to be extensively damaged by a tsunami if the Nankai Trough earthquake occurs. We use the DID and DDD approaches and show that locations with low elevation and close to the sea experienced decreases in appraised land prices compared to locations with high elevation and far from the sea. Especially, locations with less than 3.6m elevation and within 1.46km of the coastline experienced significant decreases in appraised land prices. This result implies that people have changed their location preferences regarding elevation and distance from the sea.
We develop a model where the unemployed workers in the city can find a job either directly or through weak or strong ties. We show that, in denser areas, individuals choose to interact with more ...people and meet more random encounters (weak ties) than in sparsely populated areas. We also demonstrate that, for a low urbanization level, there is a unique steady-state equilibrium where workers do not interact with weak ties, while, for a high level of urbanization, there is a unique steady-state equilibrium with full social interactions. We show that these equilibria are usually not socially efficient when the urban population has an intermediate size because there are too few social interactions compared to the social optimum. Finally, even when social interactions are optimal, we show that there is over-urbanization in equilibrium.
High-speed rail integrates regions and cities, and thus can possibly have significant impacts on the distribution of economic activities. Using the opening and extensions of a high-speed rail, ...Shinkansen, in Kyushu, Japan, we examine its effects on land prices in urban agglomerations, which would reflect changes in the distribution of economic activities across urban agglomerations. We estimate hedonic price equations to conduct a difference-in-differences analysis. We find that the large metropolitan areas gained from the high-speed rail by experiencing increases in land prices, whereas small metropolitan areas located between them lost by experiencing decreased land prices. However, such positive effects are shown to be limited to areas close to Shinkansen stations.
The two most clinically serious eating disorders are anorexia nervosa and bulimia nervosa. A drive for thinness and fear of fatness lead patients with anorexia nervosa either to restrict their food ...intake or binge-eat then purge (through self-induced vomiting and/or laxative abuse) to reduce their body weight to much less than the normal range. A drive for thinness leads patients with bulimia nervosa to binge-eat then purge but fail to reduce their body weight. Patients with eating disorders present with various gastrointestinal disturbances such as postprandial fullness, abdominal distention, abdominal pain, gastric distension, and early satiety, with altered esophageal motility sometimes seen in patients with anorexia nervosa. Other common conditions noted in patients with eating disorders are postprandial distress syndrome, superior mesenteric artery syndrome, irritable bowel syndrome, and functional constipation. Binge eating may cause acute gastric dilatation and gastric perforation, while self-induced vomiting can lead to dental caries, salivary gland enlargement, gastroesophageal reflux disease, and electrolyte imbalance. Laxative abuse can cause dehydration and electrolyte imbalance. Vomiting and/or laxative abuse can cause hypokalemia, which carries a risk of fatal arrhythmia. Careful assessment and intensive treatment of patients with eating disorders is needed because gastrointestinal symptoms/disorders can progress to a critical condition.
Natural plant populations exhibit genetic variation in defense traits against herbivores. Despite a growing body of evidence for herbivore-mediated selection on plant defenses, we still know little ...about how genetic variation persists in antiherbivore defense traits. Here we present field and experimental evidence for herbivore-mediated frequency-dependent selection that promotes the maintenance of trichome-producing (hairy) and trichomeless (glabrous) plants of Arabidopsis halleri subsp. gemmifera. First, in a natural population where the specialist leaf beetle Phaedon brassicae was prevalent, hairy plants were damaged less when the frequency of neighboring glabrous plants increased. Furthermore, temporal variation in the frequency of the two plant morphs showed that rarer morphs increased in frequency at the scale of 1-m-diameter patches between survey years. Using a mesocosm experiment, we demonstrated a rare-morph advantage for defense (leaf damage and herbivore abundance) and reproduction (flower and clone production) between hairy and glabrous plants in the presence of P. brassicae. However, this rare-morph advantage was not detected when beetles were absent, with glabrous plants having higher reproduction than hairy plants under these conditions regardless of frequency conditions. These findings highlight the overlooked but potentially critical role of herbivore-mediated apparent interaction in maintaining plant defense polymorphism.
Frequency-dependent selection (FDS) is an evolutionary regime that can maintain or reduce polymorphisms. Despite the increasing availability of polymorphism data, few effective methods are available ...for estimating the gradient of FDS from the observed fitness components. We modeled the effects of genotype similarity on individual fitness to develop a selection gradient analysis of FDS. This modeling enabled us to estimate FDS by regressing fitness components on the genotype similarity among individuals. We detected known negative FDS on the visible polymorphism in a wild Arabidopsis and damselfly by applying this analysis to single-locus data. Further, we simulated genome-wide polymorphisms and fitness components to modify the single-locus analysis as a genome-wide association study (GWAS). The simulation showed that negative or positive FDS could be distinguished through the estimated effects of genotype similarity on simulated fitness. Moreover, we conducted the GWAS of the reproductive branch number in Arabidopsis thaliana and found that negative FDS was enriched among the top-associated polymorphisms of FDS. These results showed the potential applicability of the proposed method for FDS on both visible polymorphism and genome-wide polymorphisms. Overall, our study provides an effective method for selection gradient analysis to understand the maintenance or loss of polymorphism.
We examine the possible impacts of demographics on outcomes of competition for capital in political economy. For this, we develop a multi-region overlapping generations model, wherein public good ...provision financed by capital taxation is determined by majority vote. When population is growing, younger people represent the majority, whereas when it is decreasing, older people are in majority. We uncover the possible externalities arising from political processes as well as capital mobility and show that an inefficiently high capital tax rate is more likely to emerge in an economy with decreasing population than in one with growing population.
The relevance of interspecific resource competition in the context of community assembly by herbivorous insects is a wellknown topic in ecology. Most previous studies focused on local species ...assemblies that shared host plants. Few studies evaluated species pairs within a single taxon when investigating the effects of host plant sharing at the regional scale. Herein, we explore the effect of plant sharing on the geographical co-occurrence patterns of 232 butterflies distributed across the Japanese archipelago; we use two spatial scales (10 × 10 and 1 × 1 km grids) to this end. We considered that we might encounter one of two predictable patterns in terms of the relationship between co-occurrence and host sharing among butterflies. On the one hand, host sharing might promote distributional exclusivity attributable to interspecific resource competition. On the other hand, sharing of host plants may promote co-occurrence attributable to filtering by resource niche. At both grid scales, we found significant negative correlations between host use similarity and distributional exclusivity. Our results support the hypothesis that the butterfly co-occurrence pattern across the Japanese archipelago is better explained by filtering via resource niche rather than interspecific resource competition.
An increasing number of field studies have shown that the phenotype of an individual plant depends not only on its genotype but also on those of neighboring plants; however, this fact is not taken ...into consideration in genome-wide association studies (GWAS). Based on the Ising model of ferromagnetism, we incorporated neighbor genotypic identity into a regression model, named "Neighbor GWAS". Our simulations showed that the effective range of neighbor effects could be estimated using an observed phenotype when the proportion of phenotypic variation explained (PVE) by neighbor effects peaked. The spatial scale of the first nearest neighbors gave the maximum power to detect the causal variants responsible for neighbor effects, unless their effective range was too broad. However, if the effective range of the neighbor effects was broad and minor allele frequencies were low, there was collinearity between the self and neighbor effects. To suppress the false positive detection of neighbor effects, the fixed effect and variance components involved in the neighbor effects should be tested in comparison with a standard GWAS model. We applied neighbor GWAS to field herbivory data from 199 accessions of Arabidopsis thaliana and found that neighbor effects explained 8% more of the PVE of the observed damage than standard GWAS. The neighbor GWAS method provides a novel tool that could facilitate the analysis of complex traits in spatially structured environments and is available as an R package at CRAN ( https://cran.rproject.org/package=rNeighborGWAS ).
We develop a multicountry model of illegal immigration with equilibrium unemployment. Two geographic cases are considered. One has two destinations adjacent to the source country while the other has ...just one destination country adjacent to it. In both cases, the equilibrium border control proves insufficient compared with the joint optimum, calling for enforcement by federal authorities. Absent such authorities, delegating border control to the country with a larger native labor force can improve each destination country’s welfare. In contrast, the equilibrium internal enforcement policy is efficient, obviating enforcement by supranational authorities.
PDF
