Optimal exercise of American put options near maturity: A new economic perspective

Review of Derivatives Research - The critical price $$S^{*}\left( t\right) $$ of an American put option is the underlying stock price level that triggers its immediate optimal exercise. We provide...     

How to control a chaotic economy?

An economic system which exhibits chaotic behaviour has been stabilized on various periodic orbits by use of the Ott-Grebogi-Yorke method. This procedure has been recently applied to controlling chaotic phenomena in physical, chemical and biological systems. We adopt this method successfully for Feichtinger's generic model of two competing firms with asymmetrical investment strategies. We show that the application of this control method to the particular economic process considered brings a substantial advantage: one can easily switch from a chaotic trajectory to a regular periodic orbit and simultaneously improve the system's economic properties. Numerical simulations are presented in order to illustrate the effectiveness of the whole procedure.The work was supported by the Alexander von Humboldt-Stiftung and by the Polish National Council (KBN) Grant No 2 P302 038 04.     

Modeling defaults of companies in multi-stage supply chain networks

The interest in supply chain networks and their analysis as complex systems is rapidly growing. The physical approach to the topic draws on the concept of heterogenous interacting agents. The interaction among agents is considered as a repeated process of orders and production. The dynamics of production in the supply chain network which we observe is nonlinear due to the random failures in processes of orders and production. We introduce an agent-based model of a supply chain network which represents in more detail the real economic environment in which firms operate. We focus on the influence of local processes on the global economic behavior of the system and study how the proposed modifications change the general properties of the model. We observe collective bankruptcies of firms, which lead to self-emerging network structures. Our results give insight into the dynamics of default processes in supply chain networks, which have important implications both for risk managers and policy makers. Based on the simulations we show that agent-based modeling is a powerful tool for optimization of supply chain networks.     

挑战治疗:医院必须重新思考加强治疗质量的激励行为

医疗（healthcare）产业是美国标准普尔500指数中位于金融服务和信息技术之后的第三大行业。基于对工业所贡献的知识、劳动力和原料的数量,医疗产业毫无疑问地成为当今社会的重要经济支柱。     

Exclusionary discounts

We consider a two-period model with two sellers and one buyer. Although we assume it is efficient for the buyer to purchase from both sellers in each period, we show that when the buyer's valuations are inter-temporally linked and at least one seller is financially constrained, exclusion can sometimes arise in equilibrium (i.e., the buyer purchases all of its requirements from the same seller in each period). The exclusionary equilibria are supported by contract offers in which the excluding seller's incremental price to supply the contestable part of demand is below its marginal cost and sometimes negative. Our findings contribute to the literatures on market-share contracts, bundling, all-units discounts, and loyalty discounts.     

Factors Determining the Development of Non-cash Payments in Rural Areas in Poland

This article aims at characterization and assessment of the financial behaviors of rural dwellers on non-cash payment markets and identification of factors determining the intensity of using individual methods of payment by the inhabitants of rural areas. The main source of data used for analysis and inference was information originating from the authors＇ own investigations conducted in 2013 on a group of 500 rural households and on a group of 150 trade and service points operating in non-urbanized areas. This work made use of statistical summary measures and Z2 independence test. According to the results of the conducted studies, forms of payment used by rural dwellers depend on many variables, of demographic, economic, and psychological character. Cash payments are more frequently used by persons possessing vocational or secondary education, elderly people, old-age pensioners, annuitants, or households with lower incomes. Also, persons who do not trust financial institutions or do not perceive benefits resulting from the use of non-cash instruments prefer cash. It is a group of households which require urgent educational activities in the area of non-cash payment instruments. A significant barrier to using non-cash payment instruments by rural dwellers was a limited access to non-cash channels. It is connected in the first place with a poorer development of financial infrastructure in rural areas （banks or cash points）, insufficient Internet access conditioning a possibility to use electronic banking points, and also a worse development of credit card acceptance network. As has been demonstrated by the results of conducted studies, the main reason for a lack of point of sale （POS） terminals in retail and service-providing points operating in rural areas, in the opinion of their owners, is the very high interchange fee （50% indications）, which under Polish conditions is one of the highest in the European Union （EU）.     

Institutional investors and stock returns volatility: Empirical evidence from a natural experiment

In this paper, we provide empirical evidence on the impact of institutional investors on stock market returns dynamics. The Polish pension system reform in 1999 and the associated increase in institutional ownership due to the investment activities of pension funds are used as a unique institutional characteristic. Performing a Markov-switching-GARCH analysis we find empirical evidence that the increase of institutional ownership has temporarily changed the volatility structure of aggregate stock returns. The results are interpretable in favor of a stabilizing effect on index stock returns induced by institutional investors.