Optimal Social Insurance with Endogenous Health*

In this paper, I analyze optimal insurance against unemployment and disability in a private information economy with endogenous health and search effort. Individuals can reduce the probability of becoming disabled by exerting prevention effort. I show that the optimal sequence of consumption is increasing for a working individual and constant for a disabled individual. During unemployment, decreasing benefits are not necessarily optimal. The prevention constraint implies increasing benefits while the search constraint demands decreasing benefits while being unemployed. However, if individuals respond sufficiently to search incentives, the latter effect dominates the former and the optimal consumption sequence is decreasing during unemployment.     

Double continuation regions for American and Swing options with negative discount rate in Lévy models

In this paper, we study perpetual American call and put options in an exponential Lévy model. We consider a negative effective discount rate that arises in a number of financial applications including stock loans and real options, where the strike price can potentially grow at a higher rate than the original discount factor. We show that in this case a double continuation region arises and we identify the two critical prices. We also generalize this result to multiple stopping problems of Swing type, that is, when successive exercise opportunities are separated by i.i.d. random refraction times. We conduct an extensive numerical analysis for the Black–Scholes model and the jump‐diffusion model with exponentially distributed jumps.     

Organisational regulatory legitimacy,entrepreneurial orientation,and SME innovation: an optimal distinctiveness perspective

The optimal distinctiveness perspective argues that firms face competing pressures to be both ‘like’ and ‘different from’ their peers. On the one hand, institutional scholars assert that firms need to be similar to peers in order to gain legitimacy. On the other hand, strategy scholars insist that firms need to strive to be different to gain competitive advantage. In order to enrich the optimal distinctiveness perspective, the present study builds a conceptual model that addresses the relationships among organisational regulatory legitimacy, entrepreneurial orientation, and SME innovation under the context of China’s transition economy. Our empirical results show that organisational regulatory legitimacy has an inverted-U relationship with SME innovation. Further, entrepreneurial orientation strengthens this inverse-U shaped relationship. That is, entrepreneurial orientation magnifies both the positive and the negative effect of organisational regulatory legitimacy on SME innovation. This study echoes to the call to conduct broader optimal distinctiveness research by integrating institutional theory and strategic management. Furthermore, our findings provide new evidence for the strategic balance perspective of optimal distinctiveness.     

On Targeting Frameworks And Optimal Monetary Policy

We show that speed limit policy, a monetary policy strategy that focuses on stabilizing inflation and the change in the output gap, consistently outperforms flexible inflation targeting and flexible price level targeting in empirical medium‐scale DSGE models under discretionary policymaking. In contrast to small‐scale New Keynesian models, this welfare ranking of the targeting frameworks is not overturned when inflation dynamics are mostly backward‐looking. Importantly, the performance of the speed limit policy shows less sensitivity to its parameterization than other frameworks that target the inflation rate or the price level.     

Optimal insurance under rank‐dependent utility and incentive compatibility

Bernard, He, Yan, and Zhou (Mathematical Finance, 25(1), 154–186) studied an optimal insurance design problem where an individual's preference is of the rank‐dependent utility (RDU) type, and show that in general an optimal contract covers both large and small losses. However, their results suffer from the unrealistic assumption that the random loss has no atom, as well as a problem of moral hazard that provides incentives for the insured to falsely report the actual loss. This paper addresses these setbacks by removing the nonatomic assumption, and by exogenously imposing the “incentive compatibility” constraint that both indemnity function and insured's retention function are increasing with respect to the loss. We characterize the optimal solutions via calculus of variations, and then apply the result to obtain explicitly expressed contracts for problems with Yaari's dual criterion and general RDU. Finally, we use numerical examples to compare the results between ours and Bernard et al.     

Educational Development in South Sudan: Conscious Design or Spontaneous Order?

Educational development is key to the future prosperity of South Sudan. Officially the situation appears bleak with up to 50 per cent of primary‐aged children out of school, high reported dropout rates and poor attainment. Those involved in the development of education, government departments, international agencies, individuals and communities are each following one of two different approaches as they seek to extend the reach of education. The article suggests that these different approaches arise because those involved hold to either a conscious‐design or a spontaneous‐order model for educational development. The article looks at the recent development of schools in Juba, the capital of South Sudan, in the light of these two theories and finds, despite the rhetoric of the official reports, that most growth is organic and that most recent educational development is emerging spontaneously.     

Defining Capitalism

This article aims to incorporate the essential features of capitalism in an operational definition that identifies capitalism per se (pure laissez‐faire capitalism), and clearly excludes variations such as welfare capitalism and crony capitalism. By concisely highlighting the fundamental structures and mechanisms of capitalism, this essential definition facilitates defences of it that are more robust than those ordinarily offered. It also clarifies the relation between capitalism and phenomena with which it is frequently associated, and suggests a straightforward way of identifying and measuring the extent of capitalism in mixed economies.     

寡头博弈模型中的时间记忆性质与预期对模型稳定性的影响

公平竞争是市场经济的灵魂,是发挥市场力量的关键.研究寡头垄断企业的竞争行为和竞争环境对中国强化反垄断,构建更加安全公平、有效竞争的经济市场意义重大.梳理寡头垄断企业中的价格竞争和产量竞争中的模型稳定性研究情况,通过模型的边界均衡点和局部均衡点来分析模型的稳定性,对寡头博弈模型中时间的记忆性与预期对模型稳定性的影响进行分析.     

中国水资源利用秩序评价

水资源利用秩序反映了水资源供给侧效率和需求侧公平的程度。采用秩序模型对我国30个省级行政区2008—2017年的水资源利用状态进行测度,通过测量高低收入人群收入差距的变动状况度量公平程度,使用数据包络分析法将全要素生产率的增长进行分解,从而度量其效率发挥状况,将二者综合,计算水资源总秩序水平。研究结果表明:我国大多数省级行政区水资源利用纵向秩序较好、横向秩序较差,因此应采取措施,以保障水资源利用秩序保持在较高且比较稳定的水平上。     

The dynamics of ex-ante weighted spread: an empirical analysis

We model the evolution of the ex-ante weighted spread (EWS) embedded in an open Limit Order Book (LOB) and investigate the impact of observed market-related variables on the spread. Our modeling involves decomposing the joint distribution of the weighted spread into simple and interpretable distributions. Our main results have several implications: (i) EWS features high persistence in autocorrelation; (ii) lower-level LOB remains liquid even after a high trade imbalance; (iii) lower- and higher-level LOB react to temporal spread change and trade imbalance in different ways; and (iv) both trade durations and quote durations have seasonality effects. We also show, through a simple high frequency trading exercise, that the use of the model can be economically important. Further, our model provides an estimation of market resilience.