Health Insurance and the Demand for Medical Care: a Case Study from China

Standard insurance theory expects that expenditures and coverage should be positively correlated, for two main reasons: first, high risky individuals prefer to choose a more generous coverage (selection effect); second, a more extensive coverage may increase health costs (incentive effect). We try to empirically separate the selection effect and incentive effect on the health care expenditures with a novel Chinese dataset. With our estimation, we do find the evidences of selection effect, but fail to find the incentive effect. Besides, we also find some evidences of Physician-Induced Demand

Order Flow and Exchange Rate Dynamics in Continuous Time: New Evidence from Martingale Regression

The so-called “foreign exchange rate determination puzzle” has been a hard topic in international finance for several decades. The puzzle illustrates the weak explanatory power of macroeconomic-based models of the nominal exchange rate fluctuations. We investigate the foreign exchange rate determination puzzle in a continuous-time framework. Following the market microstructure literature, a simple model of the determination of foreign exchange rates is developed, and the model concludes a result which is essentially a continuous-time version of the equation in Evans and Lyons (2002a). For estimation, we take an advantage of a newly-developed econometric tool based on a time change from calendar to volatility time. With this new estimation methodology, our results indicate that the effect of order flow on exchange rate is significantly improved compared with the traditional econometric tools. Keywords: Order Flow; Time-Change Sampling; Martingale Estimator JEL Classifications: C22; G15; G1

An Analytical Model for Adsorption and Diffusion of Atoms/Ions on Graphene Surface

Theoretical investigations are made on adsorption and diffusion of atoms/ions on graphene surface based on an analytical continuous model. An atom/ion interacts with every carbon atom of graphene through a pairwise potential which can be approximated by the Lennard-Jones (L-J) potential. Using the Fourier expansion of the interaction potential, the total interaction energy between the adsorption atom/ion and a monolayer graphene is derived. The energy-distance relationships in the normal and lateral directions for varied atoms/ions, including gold atom (Au), platinum atom (Pt), manganese ion (Mn 2+ ), sodium ion (Na 1+ ), and lithium-ion (Li 1+ ), on monolayer graphene surface are analyzed. The equilibrium position and binding energy of the atoms/ions at three particular adsorption sites (hollow, bridge, and top) are calculated, and the adsorption stability is discussed. The results show that H-site is the most stable adsorption site, which is in agreement with the results of other literatures. What is more, the periodic interaction energy and interaction forces of lithium-ion diffusing along specific paths on graphene surface are also obtained and analyzed. The minimum energy barrier for diffusion is calculated. The possible applications of present study include drug delivery system (DDS), atomic scale friction, rechargeable lithium-ion graphene battery, and energy storage in carbon materials

Examining the impact of carbon constraints on the capital structure of Chinese power enterprises

China’s power system will face more constraints of the carbon emission reduction policy under the goal of “double carbon”, it is particularly important to study the impact of carbon constraints on the capital structure of power enterprises. Commencing the viewpoint of static and dynamic, this research regards the implementation of China’s carbon pilot policy as a quasi-natural experiment, using DID method, sys-GMM model and some robustness tests to examine how the carbon constraint affects the capital structure of power companies from 2008 to 2020. The empirical results show that the financial leverage is significantly reduced after the implementation of China’s carbon pilot policy. Moreover, the mandatory implementation of carbon emission trading mechanism makes heavy emission enterprises such as power enterprises face greater pressure on emission reduction, resulting in an increase in the risk of financial distress, reducing debt financing and equity financing of power enterprises, which promotes enterprises to decrease financial leverage. In addition, the article verifies another possibility, the enhancement of carbon constraints leads to the reduction of carbon-intensive investment rather than the increase of financial distress risk, so as to reduce the asset-liability ratio. However, the coefficient of interactive items is not significant. Further analysis indicates that the decline of financial leverage is unlikely to be caused by changes in investment