General Equilibrium Conditions Research Articles

High-speed rail construction and market access of cities: Empirical evidence from China

<abstract> <p>After decades of rapid development, economic level has undergone qualitative changes in both aggregate and structural terms in China. This paper introduces the concept of market access, which argues that there are externalities to the opening of high-speed railways (HSRs) and that the accessibility of cities without high-speed railways is similarly affected by the opening of high-speed railways in other cities and investigates the impact of the opening of high-speed railways on the market access of cities. By drawing on Herzog's estimation framework, general equilibrium conditions for trade are estimated and a derived simplified model is used to determine a method for measuring cities' ability to enter the market. A systematic study of the <italic>market access</italic> indicator methodology for assessing transport infrastructure improvements is conducted to examine the spatial and temporal evolution of high-speed rail construction in China, measure the changes in market access due to high-speed rail and conduct a characteristic factual analysis based on the results obtained. The paper finds that the average inter-city travel time in China fell by 2.27 hours, i.e., 15.67%, from 2015 to 2019, with the marginal contribution to the decline in travel time coming mainly from the opening of HSRs. Over the 10 years from 2010 to 2019, the logarithm of access to market capacity for Chinese cities increased by around 50%, with the construction of high-speed railways leading to a substantial increase in access to market capacity. Overall, this paper focuses on the scientific method of measurement to provide a better objective understanding of the impact and evolution of high-speed rail construction on the market access of cities in China.</p> </abstract>

General invariance and equilibrium conditions for lattice dynamics in 1D, 2D, and 3D materials

The long-wavelength behavior of vibrational modes plays a central role in carrier transport, phonon-assisted optical properties, superconductivity, and thermomechanical and thermoelectric properties of materials. Here, we present general invariance and equilibrium conditions of the lattice potential; these allow to recover the quadratic dispersions of flexural phonons in low-dimensional materials, in agreement with the phenomenological model for long-wavelength bending modes. We also prove that for any low-dimensional material the bending modes can have a purely out-of-plane polarization in the vacuum direction and a quadratic dispersion in the long-wavelength limit. In addition, we propose an effective approach to treat invariance conditions in crystals with non-vanishing Born effective charges where the long-range dipole-dipole interactions induce a contribution to the lattice potential and stress tensor. Our approach is successfully applied to the phonon dispersions of 158 two-dimensional materials, highlighting its critical relevance in the study of phonon-mediated properties of low-dimensional materials.

DeSIRe: Departure coefficient aided Stokes Inversion based on Response functions

Future ground-based telescopes, such as the 4-metre class facilities DKIST and EST, will dramatically improve on current capabilities for simultaneous multi-line polarimetric observations in a wide range of wavelength bands, from the near-ultraviolet to the near-infrared. As a result, there will be an increasing demand for fast diagnostic tools, i.e., inversion codes, that can infer the physical properties of the solar atmosphere from the vast amount of data these observatories will produce. The advent of substantially larger apertures, with the concomitant increase in polarimetric sensitivity, will drive an increased interest in observing chromospheric spectral lines. Accordingly, pertinent inversion codes will need to take account of line formation under general non-local thermodynamic equilibrium (NLTE) conditions. Several currently available codes can already accomplish this, but they have a common practical limitation that impairs the speed at which they can invert polarised spectra, namely that they employ numerical evaluation of the so-called response functions to changes in the atmospheric parameters, which makes them less suitable for the analysis of very large data volumes. Here we present DeSIRe (Departure coefficient aided Stokes Inversion based on Response functions), an inversion code that integrates the well-known inversion code SIR with the NLTE radiative transfer solver RH. The DeSIRe runtime benefits from employing analytical response functions computed in local thermodynamic equilibrium (through SIR), modified with fixed departure coefficients to incorporate NLTE effects in chromospheric spectral lines. This publication describes the operating fundamentals of DeSIRe and describes its behaviour, robustness, stability, and speed. The code is ready to be used by the solar community and is being made publicly available.

Thermodynamic Derivation of Scaling at the Liquid-Vapor Critical Point.

With the use of thermodynamics and general equilibrium conditions only, we study the entropy of a fluid in the vicinity of the critical point of the liquid–vapor phase transition. By assuming a general form for the coexistence curve in the vicinity of the critical point, we show that the functional dependence of the entropy as a function of energy and particle densities necessarily obeys the scaling form hypothesized by Widom. Our analysis allows for a discussion of the properties of the corresponding scaling function, with the interesting prediction that the critical isotherm has the same functional dependence, between the energy and the number of particles densities, as the coexistence curve. In addition to the derivation of the expected equalities of the critical exponents, the conditions that lead to scaling also imply that, while the specific heat at constant volume can diverge at the critical point, the isothermal compressibility must do so.

Numerical studies on the self-heating phenomenon of elastomers based on finite thermoviscoelasticity

Due to their typical material characteristics, elastomer components are used in almost all areas of engineering. In many cases, these components are subject to large cyclic deformations which result in hysteresis and dissipation-induced self-heating. Further they are exposed to varying ambient temperatures. Increased component temperatures can lead to the loss of a function or to total failure. Therefore, it is important to understand the causes and influences of critical temperatures and to identify them early in the development process under the condition of efficient applicability. In addition to the calculation time and accuracy, this also includes the experimental effort required to identify the material parameters and perform validation measurements. Within this work, the phenomenon of dissipative heating in elastomers is investigated in a numerical study using a modified model of the finite thermoviscoelasticity. For this purpose, a sufficiently simple material model was formulated and implemented under the assumption of the quasi-incompressible material behaviour. Based on this, the type and the characteristic features of the self-heating effect are specifically considered, and its dependence on thermal and mechanical initial and boundary conditions is studied. Thus, a new suitable parameter is introduced, which is particularly useful to identify critical loads. Analogously, the identification of dissipation-sensitive temperature ranges is presented. The utility of the general steadystate equilibrium condition as initial condition is also shown. Furthermore, the influence of the material properties on the steadystate equilibrium is demonstrated for the first time through parameter studies. Based on these findings, recommendations for modelling, calculation and experimental parameterisation are proposed.

THE EFFECT OF DELAYED RETIREMENT ON SOCIAL WELFARE IN CHINA FROM THE PERSPECTIVE OF THE PENSION REPLACEMENT RATE

This study cuts through the pension replacement rate and aims to investigate the impact of delayed retirement on social welfare. First, this study establishes a two-period overlapping generations model and obtains the effect of delayed retirement on the replacement rate under general equilibrium conditions. Second, this paper uses actuarial and statistical methods to build a pension balance model and specifically analyzes the effect of delayed retirement on the pension replacement rate on different income groups under local equilibrium conditions. The study finds that when the contribution base and other parameters do not change, the retirement age and the replacement rate move in the same direction. When the increase in the retirement age becomes larger, the proportion of the replacement rate also increases gradually becoming larger. The increase in the range of the pension replacement rate of the high-income group is greater than for the low- and middle-income groups.

Two-variable nullcline analysis of ionic general equilibrium predicts calcium homeostasis in ventricular myocytes.

Ventricular contraction is roughly proportional to the amount of calcium released from the Sarcoplasmic Reticulum (SR) during systole. While it is rather straightforward to measure calcium levels and contractibility under different physiological conditions, the complexity of calcium handling during systole and diastole has made the prediction of its release at steady state impossible. Here we approach the problem analyzing the evolution of intracellular and extracellular calcium fluxes during a single beat which is away from homeostatic balance. Using an in-silico subcellular model of rabbit ventricular myocyte, we show that the high dimensional nonlinear problem of finding the steady state can be reduced to a two-variable general equilibrium condition where pre-systolic calcium level in the cytosol and in the SR must fulfill simultaneously two different equalities. This renders calcium homeostasis as a problem that can be studied in terms of its equilibrium structure, leading to precise predictions of steady state from single-beat measurements. We show how changes in ion channels modify the general equilibrium, as shocks would do in general equilibrium macroeconomic models. This allows us to predict when an enhanced entrance of calcium in the cell reduces its contractibility and explain why SERCA gene therapy, a change in calcium handling to treat heart failure, might fail to improve contraction even when it successfully increases SERCA expression.

BANK’S INVESTMENT ACTIVITY

The article considers the investment system that is determined by the investment activity of financial institutions. The banking system is a dynamic system, the basis of the economic infrastructure of the market. The bank's investment operations are a complex process because the bank can be both an object and an investor. The bank's investment choices are influenced by the following major factors: expected rate of return, tax characteristics, mortgage requirements, risks.The stability of the banking system depends on the general equilibrium conditions between accumulation and investment demand. The state of the banking system affects investment. The structure of the modern banking system in Ukraine is in line with Western counterparts, and the domestic legal framework in the banking sector is perfect enough to regulate banking processes and ensure the stability of the banking sector. In a broader context, international investment processes are influenced by: the state of development of the world economy, international factor and investment markets; stability of the world monetary system; development of international investment infrastructure and the like. In the context of globalization, international investment is influenced by the interacting processes of trans nationalization and regional economic integration. The effects of global economic factors, on the one hand, offset some of the differences between countries, and on the other, it creates a macro environment for large-scale activity of international entities and investment institutions.

Assessing the Marshall–Lerner condition within a stock-flow consistent model

Abstract We derive the general equilibrium condition for the terms of trade in a two-country economy model. We show that the Marshall–Lerner condition is only a special case of this condition, in which a full exchange rate pass-through to import prices is assumed. In fact, the Marshall–Lerner condition is not even a ‘useful approximation’ of the general condition. For the full pass-through assumption has destabilising, rather than stabilizing, effects, when it is introduced in a stock-flow consistent dynamic model. More generally, the higher (lower) the pass-through, the slower (quicker) is the adjustment of the economy towards the equilibrium. This is tantamount to saying that the speed of adjustment is a positive function of the strategic behaviour of the exporters, who attempt to retain their market share by keeping their foreign currency-denominated prices unchanged.

Sensitivity of using stable water isotopic tracers to study the hydrology of isolated wetlands in North Florida

Hydrology of forested wetlands is critical to the ecosystem functions and services of the forests. Our understanding of the hydrology of those wetlands, however, is very limited most likely due to the tediousness and costs of monitoring those scattered small wetlands by the traditional methods. Stable isotope ratios of oxygen (δ18O) and hydrogen (δ2H) in water may provide us a much simpler alternative to study the hydrology of those wetlands. We investigated the sensitivity and resolution of using natural stable water isotopes to quantify the hydrology of those isolated wetlands in the forests of North Florida. The observed Local Meteoric Water Line (LMWL) [δ2H = 7.7*δ18O + 9.2 (r2 = 0.97, n = 202)] followed closely to the Global Meteoric Water Line (GMWL), indicating the local rains were formed following a general isotopic equilibrium condition. Using data collected between 2014 and 2017, we observed a negative linear correlation between monthly total rain and the weight of its isotopic signature. There was no significant effect of temperature or humidity on the isotopic signatures of the rains. The water isotopes of the ephemeral ponds and sinks, on the other hand, were significantly enriched relative to the precipitation. The local evaporation lines (LEL) of the studied ephemeral ponds and sinks indicated significant evaporation. The isotope data indicated that the ephemeral Pond 55 and Pond 12 were rain fed while the water source to Blue Sink was a mixture of precipitation and groundwater. We showed that the significant differences in stable water isotopic signatures among the precipitation (especially during tropical storms and hurricanes), surface water and ground water can be used to trace the hydrological budgets and processes of forested wetlands in North Florida.

Potential Economic Impacts of Allocating More Land for Bioenergy Biomass Production in Virginia

The growing attention to renewable energy and rural development has created greater demand for production of biomass feedstock for bioenergy. However, forest growth rates and the amount of land in most existing forests may not be sufficient to sustainably supply the forest biomass required to support existing forest products industries and the expanding bioenergy industry. Additionally, concerns about agricultural land use competition have dampened expansion of biomass production on agricultural land base. One of the ways to meet the growing forest biomass feedstock demand for bioenergy production is by allocating currently marginal non-forested land for growing bioenergy feedstocks. In Virginia, about 80% of forestland is under nonindustrial private forest ownership. The land use allocation decisions of these private owners are critical for the supply of the forest biomass feedstock to support bioenergy production. We apply a computable general equilibrium model to assess the economy-wide impacts of forestland owners’ willingness to plant pine on non-forested land for woody bioenergy in Virginia. We consider three counterfactual scenarios of biomass feedstock supply increase as intermediate demand for bioenergy production based on forestland owners’ willingness to accept biomass bid prices to set aside more non-forested land for biomass production in Virginia under general equilibrium conditions. Overall, the results show an increase in social welfare and household utility but a marginal decline in GDP. However, increased demand of biomass from logging sector depressed the manufacturing sector (the wood manufacturing sub-sector particularly), which also relies on the logging sector for its intermediate inputs. Results from this study provide insights into the bioenergy land use competition debate, and pathways towards sustainable bioenergy feedstock supply.

Absent Collusion, Can Micro Level Discrimination Aggregate into Macro Level Discrimination?

The literature on `empathy' empirically establishes empathy as a source of implicit discrimination that induces disparate impacts. This study provides formal theoretical validation for empathy as source of implicit discrimination that induces disparate impacts. Metrics for `disparate impact' - as induced by empathy - that compare `proportions of different stereotypes' are shown to amplify, rather than dampen bent towards empathy in populations of economic agents. In of themselves, neither of university brands nor diversity initiatives have character of sufficiency conditions for remediation of disparate impact. Disparate impact then, is a microeconomic phenomenon, which, absent collusion, but yet ubiquity of stereotypes in decision making roles, becomes systemic. Importantly, inclusive of empathy, but yet irrespective of specific source of implicit discrimination, applied to ratings of candidates for jobs or promotions, none of means, variances, nor measures of consistency, such as Cronbach Alpha are robust to detection of incidence of a disparate impact. The formal theory arrives at necessary conditions that, applied to rating outcomes facilitate inference of a disparate impact in context of hiring or promotion processes that transpire in organizations. In aggregate, while the basis for filing of charges of disparate impact remains rooted in stereotypes, there is arrival at non-stereotypical scientifically formulated general equilibrium conditions for determination of incidence of a disparate impact. Given absence of non-stereotypical and scientifically formulated metrics for determination of disparate impact has resulted in floundering of such cases in U.S. courts, formal theoretical outcomes have pragmatic importance for facilitation of improvements to policing of discrimination in context of legal doctrine of disparate impact.

Teaching Nano-Thermodynamics: Gibbs Energy of Single-Component Nanoparticles

Much attention has been paid to thermodynamic modeling of nanosystems. A common approach consists in addition of a surface/interface term to the Gibbs energy of bulk materials and application of general conditions of equilibrium. Some discrepancy still remains dealing with the expression for surface contribution to molar Gibbs energy and chemical potential of components. It is shown, that due to the nonextensive nature of the surface area, these contributions are different for molar and partial molar quantities. The consistent expressions for the molar Gibbs energy and chemical potential of a single-component spherical nanoparticle are put forward along with the simple derivation of the Kelvin and Gibbs-Thomson equations.

International Trade Theory and the Exchange Rate: A Microeconomic Approach

This is an essay to show the rigorous connection between the neoclassical theory of trade, i.e. the Heckscher-Ohlin model in the context of General Equilibrium conditions, and the real exchange rate as determined by local and foreign prices in a common currency, i.e. the Purchasing Power Parity doctrine. The approach is strictly microeconomic. The purpose of the essay is to analyze the mechanism through which the exchange rate devaluation works for correcting the foreign trade deficit; but considering that, in the real world, this mechanism is not isolated from the influence of other macroeconomic and monetary variables. Some of the most important critiques are presented.

Spontaneous formation of non-uniform double helices for elastic rods under torsion

The spontaneous formation of double helices for filaments under torsion is common and significant. For example, the research on the supercoiling of DNA is helpful for understanding the replication and transcription of DNA. Similar double helices can appear in carbon nanotube yarns, cables, telephone wires and so forth. We noticed that non-uniform double helices can be produced due to the surface friction induced by the self-contact. Therefore an ideal model was presented to investigate the formation of double helices for elastic rods under torque. A general equilibrium condition which is valid for both the smooth surface and the rough surface situations is derived by using the variational method. By adding further constraints, the smooth and rough surface situations are investigated in detail respectively. Additionally, the model showed that the specific process of how to twist and slack the rod can determine the surface friction and hence influence the configuration of the double helix formed by rods with rough surfaces. Based on this principle, a method of manufacturing double helices with designed configurations was proposed and demonstrated. Finally, experiments were performed to verify the model and the results agreed well with the theory.

C-number quantum generalized Langevin equation for an open system

We derive a $c-$number Generalised Langevin Equation (GLE) describing the evolution of the expectation values $\left\langle x_{i}\right\rangle_{t}$ of the atomic position operators $x_{i}$ of an open system. The latter is coupled linearly to a harmonic bath kept at a fixed temperature. The equations of motion contain a non-Markovian friction term with the classical kernel {[}L. Kantorovich - PRB 78, 094304 (2008){]} and a zero mean \emph{non-Gaussian} random force with correlation functions that depend on the initial preparation of the open system. We used a density operator formalism without assuming that initially the combined system was decoupled. The only approximation made in deriving quantum GLE consists in assuming that the Hamiltonian of the open system at time $t$ can be expanded up to the second order with respect to operators of atomic displacements $u_{i}=x_{i}-\left\langle x_{i}\right\rangle_{t}$ in the open system around their exact atomic positions $\left\langle x_{i}\right\rangle_{t}$ (the "harmonisation" approximation). The noise is introduced to ensure that sampling many quantum GLE trajectories yields exactly the average one. An explicit expression for the pair correlation function of the noise, consistent with the classical limit, is also proposed. Unlike the usually considered quantum operator GLE, the proposed $c-$number quantum GLE can be used in direct molecular dynamic simulations of open systems under general equilibrium or non-equilibrium conditions.

Instability Paths in the Kirchhoff–Plateau Problem

The Kirchhoff–Plateau problem concerns the equilibrium shapes of a system in which a flexible filament in the form of a closed loop is spanned by a soap film, with the filament being modeled as a Kirchhoff rod and the action of the spanning surface being solely due to surface tension. Adopting a variational approach, we define an energy associated with shape deformations of the system and then derive general equilibrium and (linear) stability conditions by considering the first and second variations of the energy functional. We analyze in detail the transition to instability of flat circular configurations, which are ground states for the system in the absence of surface tension, when the latter is progressively increased. Such a theoretical study is particularly useful here, since the many different perturbations that can lead to instability make it challenging to perform an exhaustive experimental investigation. We generalize previous results, since we allow the filament to possess a curved intrinsic shape and also to display anisotropic flexural properties (as happens when the cross section of the filament is noncircular). This is accomplished by using a rod energy which is familiar from the modeling of DNA filaments. We find that the presence of intrinsic curvature is necessary to obtain a first buckling mode which is not purely tangent to the spanning surface. We also elucidate the role of twisting buckling modes, which become relevant in the presence of flexural anisotropy.

Heterogeneous Consumers and Trade Patterns in a Monopolistically Competitive Setting

The paper considers a two-country trade model of monopolistic competition featuring the heterogeneity of consumer preferences both within and across countries. The incorporation of heterogeneity into a traditional monopolistic competition setting is achieved by assuming different elasticities of substitution in the CES utility function for different consumers. The proposed setup expands on the traditional model of trade by demonstrating a richer set of country specific effects. The key question analysed in the paper is how consumer heterogeneity and trade liberalization affect markups and wages in different countries. Unlike the canonical CES-model of trade, where markups in different countries are constant and identical to each other, our model, by taking consumer heterogeneity into account, provides different markups across countries, incorporating both heterogeneity and trade specifics. The model also predicts that the larger of two countries engaged in costly trade may have a wage rate higher than, lower than or equal to that of the smaller one, depending on the general equilibrium conditions. This finding is in contrast to that of the canonical setting, where the larger country under costly trade always has a higher wage rate.

Thermodynamic Equilibrium in Relativity: Four-temperature, Killing Vectors and Lie Derivatives

The main concepts of general relativistic thermodynamics and general relativistic statistical mechanics are reviewed. The main building block of the proper relativistic extension of the classical thermodynamics laws is the four-temperature vector \beta, which plays a major role in the quantum framework and defines a very convenient hydrodynamic frame. The general relativistic thermodynamic equilibrium condition demands \beta to be a Killing vector field. We show that a remarkable consequence is that all Lie derivatives of all physical observables along the four-temperature flow must then vanish.

Perspektywy rozwoju handlu międzynarodowego nasionami oleistych – wyniki symulacji w warunkach równowagi ogólne

The aim of the paper was to assess the possibilities of development of trade in oilseeds in countries of the biggest producers of oilseeds in the world and in Poland under general equilibrium conditions and in view of progressing liberalisation of the global trade.