Climate change, along with its associated extreme and abnormal temperature events, poses risks to human health. We examine the impact of temperatures on health insurance decisions using a proprietary dataset that links critical illness insurance records with long-term, daily meteorological data. We show that both heat and cold increase health insurance purchases. The effect of heat is driven by both heightened physical health risks and the salience of unexpected, abnormal heatwaves in health insurance decisions. However, the heat impact decays with prior experience to abnormal heat events. In contrast, we find no evidence that cold temperatures either increase physical health risks or trigger a salience effect. Risk preference changes and business cycles do not explain our findings. Air conditioning mitigates heat-induced insurance demand and centralized heating system mitigates cold-induced insurance demand. Males, the elderly, and outdoor workers are more sensitive to heat compared to females, the young, and indoor workers. This research uniquely quantifies the effects of abnormal temperatures on insurance purchases, highlighting the salience effect in insurance decision-making.

We examine risk attention as an overlooked driver of insurance uptake. We leverage the COVID-19 pandemic as a natural experiment-when all COVID-related expenses were covered by public funds in China and public attention shifted to the only major under-covered source of catastrophic medical spending: critical illnesses (CI). Using a unique private CI insurance dataset with both unbound insurance applications and bound contracts, we document a rise in bound insurance contracts and a disproportionately larger increase in unbound applications, particularly among lower-risk individuals. This surge reflects the increased interest and awareness of CI risks and insurance, as well as realized CI insurance uptake. We find robust evidence that the surge is driven by heightened attention to previously overlooked CI risks, and rule out competing explanations.

In this study, we examine the impact of big data and corresponding prediction techniques on insurance risk assessment. We demonstrate that both big data and the Least Absolute Shrinkage and Selection Operator (LASSO) approach, a modern predictor selection technique, effectively improve insurance risk assessment accuracy. In an average of proxies, the out-of-sample health risk prediction accuracy improves by 106 %, in which big data, in addition to traditional insurance policy and demographic information, contributes 82.5 %, and the LASSO model contributes 17.5 %. We also demonstrate that big data obtained from smartphone use offers extra-predictive power in addition to past medical histories. We employ Adaptive Group LASSO to determine that the most fruitful data collection sources for health insurance underwriting include personal digital devices, recent travel experience, and insureds’ credit records.

Effective early identification of potentially fragile financial institutions is crucial for mitigating systemic risks due to the strong interconnection within the financial sector. For the first time, we apply the Structural Artificial Neural Network (SANN) to predict failure of financial institutions, using insurance companies as the context. The SANN is a category-wise machine learning algorithm (i.e., a category-aware learner) that extracts nonredundant information from Big Data with different categories of information. It enables the grouping of predictors into economic categories and thus allows interactions both within and across categories. We show that the SANN significantly improves the out-of-sample predictions of insurer failures, resulting in an average increase in the area under the curve (AUC) of 1.83% to 9.55% compared to traditional machine learning and logistic models, based on a sample of 2424 insurers from 17 European countries. We also document that macroeconomic and yield information provides nonredundant information in forecasting the failures, in addition to firm characteristics.

Limited research has been conducted on the optimal public-private risk-sharing for catastrophe risks. This paper develops a theoretical framework to study the risk-sharing decisions and interactions of three types of catastrophe-market participants: a large number of individuals, a large number of private insurers in a competitive market, and a government that can choose between alternatives of re/insurance or ex post relief. Our analysis shows that the optimal government intervention varies depending on the correlation levels among individual losses. For moderately positive levels of loss correlation, it is optimal for the government to offer an ex post relief program to supplement private insurance. However, for higher levels of loss correlation, government reinsurance becomes optimal, although not to the extent of replacing private insurance if the government is less efficient than private firms. In sum, as catastrophe-loss correlations increase, that is, as the risk becomes more catastrophic, more risk-sharing tools and funding are needed to maximize social welfare.

This paper studies the impact of capital regulatory reform on firm behavior. We develop a portfolio-choice model to investigate how capital regulatory reforms influence the risk-taking behavior of financial institutions with different capital adequacy levels. The model predicts that as regulation becomes more stringent, either all firms reduce their risk-taking, or there exists a capital-adequacy threshold below which risk-taking increases. The Chinese insurance solvency regulatory reform provides a unique natural experiment to examine firms' risk-taking responses to the capital shock driven by the reform. We find that increasing regulatory pressure - i.e. a more stringent regulation - induces greater risk-taking for less capital-adequate insurers, the insurers whose risk-taking the regulator most wants to reduce. We rule out the potential reverse causality that insurers' risk structures prior to the reform determine their degrees of capital shock and that insurers target low capital-adequate positions by taking more risks prior to the reform. Our results suggest that reinforcing the qualitative risk assessment, increasing the penalties of insolvent insurers, and increasing the risk sensitivity of capital requirements could be effective policy remedies for this backfiring problem.

The J-TEXT capability is enhanced compared to two years ago with several upgrades of its diagnostics and the increase of electron cyclotron resonance heating (ECRH) power to 1 MW. With the application of electron cyclotron wave (ECW), the ECW assisted plasma startup is achieved; the tearing mode is suppressed; the toroidal injection of 300 kW ECW drives around 24 kA current; fast electrons are generated with toroidal injected ECW and the runaway current conversion efficiency increases with ECRH power. The mode coupling between 2/1 and 3/1 modes are extensively studied. The coupled 2/1 and 3/1 modes usually lead to major disruption. Their coupling can be either suppressed or avoided by external resonant magnetic perturbation fields and hence avoids the major disruption. It is also found that the 2/1 threshold of external field is significantly reduced by a pre-excited 3/1 mode, which can be either a locked island or an external kink mode. The disruption control is studied by developing prediction methods capable of cross tokamak application and by new mitigation methods, such as the biased electrode or electromagnetic pellet injector. The high-density operation and related disruptions are studied from various aspects. Approaching the density limit, the collapse of the edge shear layer is observed and such collapse can be prevented by applying edge biasing, leading to an increased density limit. The density limit is also observed to increase, if the plasma is operated in the poloidal divertor configuration or the plasma purity is increased by increasing the pre-filled gas pressure or ECRH power during the start-up phase.

The coupling of multiple magnetohydrodynamic (MHD) modes can lead to mode locking and major disruption in tokamak plasmas. In the J-TEXT tokamak, the coupling between two small modes, i.e. m/n = 2/1 and 3/1 modes (m and n are poloidal and toroidal mode numbers, respectively), appears when the edge safety factor is reduced to the vicinity of 3. After the mode coupling, the toroidal phase difference between the 2/1 and 3/1 modes equals 0 in the low field side midplane. This phase relation of coupled modes leads to mutual destabilization and even major disruption. A control scheme to avoid disruption caused by coupled modes by resonant magnetic perturbations (RMPs) is presented. It is found that the application of RMP significantly changes the evolution of the coupled modes. The coupling of the 2/1 and 3/1 modes occurs earlier as the RMP amplitude increases. The RMP with moderate amplitude can suppress the growth of 2/1 and 3/1 coupled modes and hence avoid disruption. These results provide a possible strategy for the suppression of neoclassical tearing mode (NTM) seed islands on International Thermonuclear Experimental Reactor (ITER) or future fusion reactors.

It has been found that a higher-frequency rotating resonant magnetic perturbation (RRMP) can suppress a large tearing mode (TM) and avoid subsequent disruption (Li et al 2020 Nucl. Fusion 60 056022). To clarify the mechanism of the stabilizing effect of the higher-frequency RRMP, experiments on the effects of RRMPs with different frequencies on the TM amplitude are presented in this paper. After eliminating the destabilizing effect of RRMP, the statistical analysis reveals a notable negative correlation between changes in the amplitude of the TM and changes in the mode frequency. Further investigation indicates an absence of a suppressive effect of the toroidal flow on the TM. Instead, the data shows a clear linear relationship between changes in the TM amplitude and the flow shear in proximity to the resonant surface, with a high coefficient of determination ( r 2 ). Those experimental results suggest that the flow shear plays a significant role in the suppression of TMs and offer a plausible method to prevent disruptions in future devices.

This paper provides the first piece of empirical evidence regarding the impact of health cost risk on individuals’ annuitization decisions. We find that health cost risk increases the probability of individuals’ pension participation but decreases the amount of pension contributions. We show that the substitution effect of informal insurance on pensions leads to these seemingly contradictory results. The impact of health cost risk on pension participation and contributions is negative and consistent with the mainstream theory after accounting for the effect of informal insurance. The substitution effect of informal insurance on pensions is stronger, and thus mitigates the impact of health cost risk more pronounced for households that have better-educated children, lower incomes, and more informal social networks and in regions that have a higher male–female ratio, that have higher mobility, or are less developed; but this substitution effect does not differ depending on their children’s gender. This study improves our understanding of the relationship between health cost risk and individuals’ annuitization decisions as well as the role of informal insurance in this relationship.

This paper proposes a novel bus regulating strategy that improves the dynamic response of active coil current in order to providing dynamic resonant magnetic perturbation (DRMP). The DRMP power supply, adopting the topology of a thyristor rectifier linked with a resonant inverter, part of the circuit comprising a bus filter, resonant inverter and load, can be simplified as a second-order model when the bus parameters are analyzed. On this basis, a controlled resistive branch with particular open-loop pulse width modulation (PWM) control is designed, installed and experimentally shown to greatly reduce the rising time and overshoot percentage of coil current. Moreover, this strategy has advantages in terms of compactness and economics but the power consumption of the new branch should be considered.

The acceleration of the magnetic island rotation by the modulated resonant magnetic perturbation (MRMP) has been studied in J-TEXT tokamak experiments. After applying the MRMP, the phase difference between the tearing mode (TM) and MRMP, Δξ, oscillated near the effective phase difference, Δξ eff, which was defined as the time averaged value of Δξ. When the Δξ eff was closed to the—π/2, the MRMP only contributed an accelerating torque on the TM. As the result, the TM rotation frequency was increased by a few kilohertz for the optimized relative phase by small RMPs of the order of 10−5 of the toroidal field and the locked mode induced disruption was avoided. It is found that the TM rotation could be increased to a higher frequency by applying a stronger MRMP. There is a negative sinusoidal relationship between TM frequency and Δξ eff.

The spectrum effect on the penetration of resonant magnetic perturbation (RMP) is studied with upgraded in-vessel RMP coils on J-TEXT. The poloidal spectrum of the RMP field, especially the amplitudes of 2/1 and 3/1 components, can be varied by the phase difference between the upper and lower coil rows, Δϕ = ϕ top−ϕ bottom, where ϕ top and ϕ bottom are the toroidal phases of the n = 1 field of each coil row. The type of RMP penetration is found to be related to Δϕ, including the RMP penetration of either 2/1 or 3/1 RMP and the successive penetrations of 3/1 RMP followed by the 2/1 RMP. For cases with penetration of only one RMP component, the penetration thresholds measured by the corresponding resonant component are close for various Δϕ. However, the 2/1 RMP penetration threshold is significantly reduced if the 3/1 locked island is formed in advance. The changes in the rotation profile due to 3/1 locked island formation could partially contribute to the reduction of the 2/1 thresholds.

The phase difference Δ ξ between locked islands (2/1 and 3/1) has been found to influence the heat transport on the thermal quench during disruptions by numerical modeling [Hu Q et al 2019 Nucl. Fusion 59 , 016005]. To verify this experimentally, a set of resonant magnetic perturbation (RMP) coils is required to excite coupled magnetic islands with different Δ ξ . The spectrum analysis shows that the current RMP coils on J-TEXT can only produce sufficient 2/1 and 3/1 RMP fields with a limited phase difference of Δ ξ ∈[−75°, 75°]. In order to broaden the adjustable range of Δ ξ , a set of coils on the high field side (HFS) is proposed to generate 2/1 and 3/1 RMP fields with Δ ξ = 180°. As a result, RMPs with adjustable Δ ξ ∈[−180°, 180°] and sufficient amplitudes could be achieved by applying the HFS coils and the low field side (LFS) coils. This work provides a feasible solution for flexible adjustment of the phase difference between m and m + 1 RMP, which might facilitate the study of major disruptions and their control.

The rotating resonant magnetic perturbation (RMP) could lock the tearing mode (TM) and prevent disruption. It is found that the TM instantaneous frequency oscillates during TM locking on the RMP. In this work, the TM frequency oscillation was derived analytically based on the toroidal torque balance, which was verified experimentally. It is found that two peaks with higher frequency (2fTM0-fRMP) and lower frequency (fRMP) occurred in the spectrum when the window width of FFT was shorter than the TM frequency oscillating period. Those two peaks were explained analytically based on the description of TM instantaneous frequency. The independence of the temporal information and the spatial information of the TM was explained analytically and verified by the spatial structure analysis of each peaks. This work is important for mode structure identification and provides a scheme for mode coupling control.

2022年3月5日,李克强总理在年度《政府工作报告》第三部分"2022年政府工作任务"第(九)节"切实保障和改善民生,加强和创新社会治理"中,分两段阐述了医疗保障和其他社会保障工作的具体任务.医疗保障方面,报告提出要实现"居民医保和基本公共卫生服务经费人均财政补助标准分别再提高30元和5元,推动基本医保省级统筹","深化医保支付方式改革,加强医保基金监管.

We empirically investigate the trade-offs between three strategic goals of the insurance business: growth, profitability and safety. Analysing 1988 European insurance companies over 11 years with simultaneous equation models, we show that moderate firm growth is associated with high profitability, but extremely high growth is associated with low profitability (i.e. an inverse non-linear relationship). Our results show that less profitable insurers are taking more risks. Insurers that prioritise profit over growth in early periods are more likely to reach the ideal state of 'profitable growth' in later periods. Our results emphasise the need to jointly consider growth, profitability and safety in a multi-period context when evaluating firm performance.

We study how pension participation and expected pension benefits affect working-age adults’ consumption based on a nationally representative dataset from the China Health and Retirement Longitudinal Study (CHARLS) during the period 2011–2018. We find that the consumption of working-age adults who participate in China's Residents' Basic Pension is 15.4% higher than that of non-participants. Furthermore, we find that if working-age adults' expected pension benefits increase by RMB 1, their consumption will increase by RMB 0.34. Overall, our findings suggest that pension expectations are critical to the consumption decisions of working-age adults and can, therefore, positively affect total domestic consumption.

Correspondence Martin Eling, Institute of Insurance Economics, School of Finance, University of St. Gallen, Girtannerstrasse 6, 9010 St. Gallen, Switzerland. Email: martin.eling@unisg.ch Abstract New technologies may allow principals or firms to learn more quickly about the characteristics of their agents or clients—at some cost of employing that technology. We study the implications of this speed‐ versus‐cost tradeoff for equilibrium pricing and purchasing decisions in insurance markets featuring adverse selection. In particular, we study dynamic competitive equilibrium in a theoretical model featuring individuals who differ in their privately known risk types and featuring two types of insurers: conventional insurers who employ a legacy learning technology and tech insurers who employ a new technology. Equilibrium in our model features sorting of low‐risk types into tech firms and high‐risk types into conventional firms. We show, intuitively, that lowering the technology cost raises this cutoff and thus increases the equilibrium market share of tech firms. Perhaps counter‐intuitively, however, we show that adverse selection effects within the conventional market can cause an attempt by conventional insurers to catch up with tech firms—by increasing the speed at which they learn about the risk types of their insureds—to backfire and lead to an increase in the market share of tech