带量采购政策下制药企业投标过程中的价格决策分析——基于博弈论的视角

药品集中带量采购政策是中国医疗体制改革的重大举措,目的在于通过以“量”换“价”的方式,降低药品价格。采用不完全信息静态博弈和序贯博弈分析制药企业如何在投标过程中做出最优报价决策。结果表明：制药企业成本越低,最优投标报价策略下所实现的收益越高;参与竞争的制药企业越少,最优投标报价策略下所实现的收益越高;政府采购价格为顶价A与制药企业成本C的一半。基于研究结论,为完善药品集中带量采购政策,推进政企之间的利益均衡提出几点可行性建议。     

Minimal Entropy Martingale Measures of Jump Type Price Processes in Incomplete Assets Markets

We consider the incomplete assets market and assume that the market has no-arbitrage. Then there are many equivalent martingale measures associated with the market. Among them, a probability measure which minimizes the relative entropy with respect to the original probability measure P, has a special importance. Such a measure is called the minimal entropy martingale measure (MEMM). In a previous paper, we have proved the existence theorem of the MEMM for the price processes given in the form of the diffusion type stochastic differential equation. In this article we discuss the MEMM of the jump type price processes, or especially of the log Lévy processes, and we give the explicit form of MEMM.     

Buying a Home with a Resale Value: Location,Location, Location*

We develop a dynamic multiregion model, where a household's choice of housing location depends on its current wealth and its current type, and involves both consumption and investment considerations. The relative strength of the consumption motive and the investment motive determines the equilibrium pattern of residential sorting. A strong investment (consumption) motive implies sorting according to household type (wealth). The model predicts that large house‐price fluctuations are associated with a low degree of sorting by type. This prediction is consistent with evidence from US metropolitan areas when income, education, and age are used as proxies for household type.     

Bounds on European Option Prices under Stochastic Volatility

In this paper we consider the range of prices consistent with no arbitrage for European options in a general stochastic volatility model. We give conditions under which the infimum and the supremum of the possible option prices are equal to the intrinsic value of the option and to the current price of the stock, respectively, and show that these conditions are satisfied in most of the stochastic volatility models from the financial literature. We also discuss properties of Black–Scholes hedging strategies in stochastic volatility models where the volatility is bounded.     

基于PEST模型的施工企业国际工程承包业务分析

随着全球经济一体化的不断深化,我国施工企业国际工程承包业务,从数量上来看,具备了相当的规模,但相对于市场的发展来说还处于初级阶段,还存在着不少问题;从实践中来看,还有不少存在亏损状况;中国企业要想避免亏损摆脱现状,扩大市场份额,就需要付出加倍的努力。文章通过对中国施工企业的PEST分析,提出中国施工企业国际工程承包业务的发展战略。     

Equilibrium with Default and Endogenous Collateral

We study a two‐period general equilibrium model with incomplete asset markets and default. We make collateral endogenous by allowing each seller of assets to fix the level of collateral. Sellers are required to provide collateral whose first‐period value, per unit of asset, exceeds the asset price by an arbitrarily small amount. Moreover, borrowers are also required to be fully covered by the purchase, in the first period, of state‐by‐state default insurance. These insurance contracts are offered by lenders. The insurance cost or revenue is a linear charge and plays the role of a spread penalizing borrowers who will incur in default and benefiting lenders who will suffer default. Under these assumptions, equilibrium always exists.     

Optimal Hedging and Valuation of Nontraded Assets

This paper examines a number of valuation problems faced by an expected-utility-maximizing investor who, over a given time horizon, is constrained to hold an asset which cannot be replicated by dynamic trading and which therefore does not have a unique no-arbitrage price. We first derive the private valuation which the investor assigns to the nontradedasset in order to determine his optimal investment in the traded assets. We thereby show that, as part of this portfolio, the investor hedges the private valuation process of the nontraded asset, rather than its market price process. We also study the price at which the investor would be willing to sell the nontraded asset if he were subsequently prohibited from trading in it, as well as the amount the investor would be willing to pay to removethe trading restriction. All three values are shown to depend in an intuitive manner on the investor's risk aversion, the residual risk of the nontraded asset unhedged by the traded assets, the difference between the constrained holding and optimal unconstrained holding of the asset and the length of the time horizon over which the asset cannot be traded.     

The Minimal Entropy Martingale Measure and the Valuation Problem in Incomplete Markets

Let χ be a family of stochastic processes on a given filtered probability space (Ω, F, (F_t)_t∈T, P) with T?R₊. Under the assumption that the set M_e of equivalent martingale measures for χ is not empty, we give sufficient conditions for the existence of a unique equivalent martingale measure that minimizes the relative entropy, with respect to P, in the class of martingale measures. We then provide the characterization of the density of the minimal entropy martingale measure, which suggests the equivalence between the maximization of expected exponential utility and the minimization of the relative entropy.     

Italian households’ debt: the participation to the debt market and the size of the loan

This paper analyses Italian households’ participation to the debt market, separating the probability of demanding a loan from the probability of being rationed by lenders; on the supply side of the market specific attention is paid to enforcement costs of the loan contract when customers default. A new result is that the age of the household head acts essentially as a demand factor, rather than a variable influencing the lender’s choice. Both current and future households’ income increase the demand for loans and reduce credit rationing. Self-employed workers are more rationed by lenders. Credit constraints are also linked to the area where the household lives, partly because of different enforcement costs. The final part of the paper analyses the equilibrium quantity of the loan, for households who have a loan and are not constrained. The loan size is positively linked to household net wealth and income profile. An important contribution of this paper is the finding that, not only the participation to the debt market, but also the loan size is negatively affected by enforcement costs.      

Public–private partnerships: Task interdependence and contractibility

We examine the proper scope of public–private partnerships in the context of a project consisting of two tasks, building and operation of a facility. We investigate the optimal arrangement regarding bundling versus unbundling and private ownership versus public ownership. Like Bennett and Iossa (2006), we assume that the innovative activity in the building stage has impacts on, among other things, the subsequent operational cost. We relax the nature of task interdependence and study different contractual frameworks. The general insight is that given limitations in contractibility, contrary to common sense, complementarity between tasks favors unbundling over bundling.