Population Outflow from Earthquake-Stricken Areas and Resindent-led Reconstruction: A Theoretical Analysis

We build a cultural transmission model to consider an effective measure for mitigating population outflow from areas affected by the Great East Japan Earthquake. In an economy with firms and two heterogeneous agents (residents within earthquake stricken areas and around these areas), when the stable interior steady state exists in our system, first we analyze how subsidies to firms affect the steady state population share for residents in earthquake stricken areas. Depending on conditions, the policy may either succeed (an increase in the population share compared to the case with no policy) or fail (a decrease in the share). Second, even if the subsidy policy fails, resident-led reconstruction efforts could potentially increase the steady state population share for residents when subsidy is simultaneously given. From the analysis, we find that resident-led reconstruction efforts can be an effective measure to mitigate the population outflow in earthquake stricken areas

Effect of Water on the Manifestation of the Reaction Selectivity of Nitrogen-Doped Graphene Nanoclusters toward Oxygen Reduction Reaction

We investigated the selectivity of N-doped graphene nanoclusters (N-GNCs) toward the oxygen reduction reaction (ORR) using first-principles calculations within the density functional theory. The results show that the maximum electrode potentials (UMax) for the four-electron (4e–) pathway are higher than those for the two-electron (2e–) pathway at almost all of the reaction sites. Thus, the N-GNCs exhibit high selectivity for the 4e– pathway, that is, the 4e– reduction proceeds preferentially over the 2e– reduction. Such high selectivity results in high durability of the catalyst because H2O2, which corrodes the electrocatalyst, is not generated. For the doping sites near the edge of the cluster, the value of UMax greatly depends on the reaction sites. However, for the doping sites around the center of the cluster, the reaction-site dependence is hardly observed. The GNC with a nitrogen atom around the center of the cluster exhibits higher ORR catalytic capability compared with the GNC with a nitrogen atom in the vicinity of the edge. The results also reveal that the water molecule generated by the ORR enhances the selectivity toward the 4e– pathway because the reaction intermediates are significantly stabilized by water

Structural stability and aromaticity of pristine and doped graphene nanoflakes

We have quantitatively investigated the relationship between the aromaticity and structural stability of graphene nanoflakes (GNFs) using first-principles calculations. The aromaticity of each six-membered ring of GNFs is evaluated with the nucleus-independent chemical shifts (NICS). We have found that for armchair-edge GNFs, the degree of stability, that is, the edge formation energy, is proportional to the average NICS for all six-membered rings. Even for nitrogen- and boron-doped GNFs, the average NICS strongly correlates with the doping formation energy. Our results indicate that NICS is a good measure not only for the aromaticity but also for the structural stability of pristine/doped nanographene systems

A Business Cycle Model of Speculation from a Viewpoint of Minsky and Shiller Ⅰ: Construction of Model and Its Local Analysis

We construct a 3-dimensional extension of the dynamic IS-LM model, in which the money demand function depends not only on income but also on a rate of change in expected income (RCEI). We demonstrate the occurrence of limit cycles in the extended IS-LM model. Our arguments are essentially derived from the remarkable viewpoint of H. P. Minsky and J. R. Shiller concerning financial markets. We assume that the money demand negatively correlates with RCEI. Such a negative correlation results from a speculative behavior. We demonstrate that the negative correlation is an important source of unstable equilibrium and therefore, business cycles. Firstly, we transform the extended IS-LM model into a 2-dimensional Lienard system and prove the occurrence of a stable limit cycle in the Lienard system. Secondly, by using a Hopf bifurcation theorem, we demonstrate the occurrence of a Hopf cycle in the extended 3-dimensionl IS-LM model. Our model possesses two types of self-fulfilling prophecy

Monetary Policy in a Pessimistic Economy Produces a Long Stagnation with Low Interest Rates

We provide a new, simple mechanism for why a monetary policy fails and, consequently, produce a long stagnation accompanied by low interest rates. The base models we use to explain this mechanism are an IS-LM model and the IS-MP model constructed by Romer (2000, 2013). We construct dynamic versions of the base models, which possess adaptive adjustments for expected income. We incorporate two types of pessimism into the dynamic models: the pessimism in the initial condition and the (intended or unintended) pessimistic mode embedded in the models. We consider the situation where a monetary policy is implemented for the country to recover from a low economic situation. Then, we focus on the transition processes from the old equilibrium, existing before implementing the monetary policy, to the new equilibrium after implementing it. In considering these, we assume that the equilibria in the models are globally asymptotically stable. As a result of the combined effect of two types of pessimism, the economy may fall into a long stagnation accompanied by quite low interest rate. Moreover, since such pessimisms produce the long stagnation, our result exhibits a self-fulfilling prophesy. Therefore, if such pessimisms are not removed, the long stagnation may worsen and the quite low interest rates may persist for a long time. A remarkable feature of our result is that, even if demand-side fundamentals such as investment and consumption functions are not changed, the long stagnation we consider emerges merely from pessimism. In this sense, our result gives a new perspective concerning the source of a long stagnation

Dynamics of Well-being in Japan from Capability-based Perspective

This study aims to analyze dynamics of multidimensional poverty in Japan in termsof the Capability Approach (CA) as a conceptual framework. Following Alkire andFoster (2011), an multidimensinal poverty index (MPI) for Japan is proposed. Similarto Suppa (2018), our MPI is also defined without income, which enables us to compareit with conventional income-based measures. Then, the adjusted headcount ratio M0,which can be related to capability poverty, is contrasted to the usual headcount ratio.As a result, we have clarified the similarities and differences between poverty as measuredby income and poverty as evaluated by the CA in the Japanese context. UsingJapanese general social surveys for the years 2012, 2015, and 2017/18, the M0 valuesfor different subgroups as well as by year are computed and presented as an empiricalanalysis. The analysis reveals differences between income poverty and multidimensionalpoverty. Through comparisons of trends between the two over time, we find thatmultidimensional and income poverty measures differ regarding who is viewed as poor.Conversely, we also find similarities between the two. In the context of child poverty,both measures make common judgments for subgroups of variables on family’s economicbackground in a respondent’s childhood. That is, the more dire the householdfinancial situation during childhood is, the higher the values of M0 and income povertyrate are. This would be an interesting finding when considering intergenerational chainsof poverty, which has also been observed in Japan through our M0

Animal Spirits and Business CyclesⅠ: A Dynamic Model and Its Nonlinear Analysis

We construct a simple Keynesian business cycles model in which animal spirits is incorporated into the model. We assume that each firm possesses the Keynesian investment function depending on demand. Like the well-known Kaldor model, we connect the animal spirits with the degree of response of investment to demand. However, for each firm we assume that even if the level of demand is the same, the strength of it is different between upswing and downswing of income. That is, we assume that the animal spirits of each firm is strong (resp. weak) in the case where demand increases (resp. decreases). This assumption implies that the Keynesian investment function of each firm is asymmetry. Unlike many Keynesian business cycles models, we introduce a certain kind of homogeneity among such a type of investment function. Moreover, we construct a statistical model that builds a bridge between microinvestment and macro-investment and derive a nonlinear macro-investment function. By using the investment function, we construct a simple business cycles model. We demonstrate that the nonlinearity yields a limit cycle in our model and detect the occurrence of a generalized Hopf bifurcation

A Business Cycle Model of Speculation from a Viewpoint of Minsky and Shiller Ⅱ: Global Dynamic Analysis

We construct a 3-dimensional extension of the dynamic IS-LM model, in which the money demand function depends not only on income but also on a rate of change in expected income (RCEI). We demonstrate the occurrence of limit cycles in the extended IS-LM model. Our arguments are essentially derived from the remarkable viewpoint of H. P. Minsky and J. R. Shiller concerning financial markets. We assume that the money demand negatively correlates with RCEI. Such a negative correlation results from a speculative behavior. We demonstrate that the negative correlation is an important source of unstable equilibrium and therefore, business cycles. Firstly, we transform the extended IS-LM model into a 2-dimensional Lienard system and prove the occurrence of a stable limit cycle in the Lienard system. Secondly,by using a Hopf bifurcation theorem, we demonstrate the occurrence of a Hopf cycle in the extended 3-dimensionl IS-LM model. Our model possesses two types of self-fulfilling prophecy

Equilibrium Pigou Cycle

We construct a simple endogenous model that describes business cycles resulting from self-fulfilling prophecies. In our model, the goods market is assumed to be continuously cleared. Being guided by Pigou\u27s 1926 insight, we try to show that the expectation about future economy plays an important source of business cycles. We assume that firms expect the occurrence of business fluctuations. Then, the firms will try to calculate expected income. Under such an assumption, we demonstrate the occurrence of business cycles. Since the expectation of business fluctuations yields business fluctuations, the results of our model are based on self-fulfilling prophecies. Using the Hopf bifurcation theorem, we detect a limit cycle in our model. Moreover, by executing numerical simulations, we describe the possible occurrence of stable limit cycles and show that the width of such a limit cycle depends on the degree of intensity of animal spirits

Mechanism of stabilization and magnetization of impurity-doped zigzag graphene nanoribbons

Doping is an efficient way to modify the electronic structure of graphene. Although there have been a considerable number of studies on the electronic structure of impurity-doped graphene, every study has suggested a different interpretation of the appearance of impurity levels of dopants located near the so-called zigzag edge of graphene nanoribbons (GNRs). Here, we propose a charge transfer model that satisfactorily explains the change in electronic structure upon N(B) doping of zigzag GNR (ZGNR). The structural stability and electronic structure of the doped ZGNR have been investigated using first-principles calculations based on the density functional theory. The formation energy of doping increases as a function of the distance between the N(B) atom and the zigzag edge, and two tendencies are observed depending on whether the dopant is an odd or even number of sites away from the zigzag edge. Such peculiar behavior of the formation energy can be successfully explained by charge transfer between the so-called edge state localized at the edge and the 2p-state of the dopant. Such an electron (hole) transfer leads to the compensation (disappearance) of the local spin-magnetic moment at one side of the ZGNR, manifesting in the ferromagnetic ground state of ZGNR