A new condition for identifiability of finite mixture distributions

In this paper a sufficient condition for the identifiability of finite mixtures is given. This condition is less restrictive than Teicher’s condition Teicher H, Ann Math Stat 34:1265–1269 (1963) and therefore it can be applied to a wider range of families of mixtures. In particular, it applies to the classes of all finite mixtures of Log-gamma and of reversed Log-gamma distributions. These families have been already studied by Henna J Jpn Stat Soc 24:193–200 (1994) using another condition, different from Teicher’s, but more difficult to check in many cases. Furthermore, the result given in this paper is very appropiated for the case of mixtures of the union of different distribution families. To illustrate this an application to the class of all finite mixtures generated by the union of Lognormal, Gamma and Weibull distributions is given, where Teicher’s and Henna’s conditions are not applicable     

Axiomatic properties of geo-logarithmic price indices

In the axiomatic approach to composite index numbers, a list of properties is given that both price and quantity indices should satisfy in order to ensure consistent comparisons. Usually, the price index is selected first and its cofactor is consequently adopted as the (implicit) quantity index. Unfortunately, even if the price index has good axiomatic properties, its cofactor need not, so the implicit quantity comparison may be axiomatically inconsistent. In this paper, we give a comprehensive study of a family of price indices sharing good axiomatic properties (proportionality, commensurability, and homogeneity) together with their cofactors. This family, called geo-logarithmic, is relevant also because of the empirical circumstance that all known price indices sharing such properties with their cofactors belong to it or can be obtained from geo-logarithmic index numbers through simple transformations. Thus, the geo-logarithmic family seems to play a central role when the joint consistency of price and quantity comparisons is concerned.     

上海住房价格指数完善研究

在中国房地产的快速发展过程中,房地产行业的风险问题日益突出。用科学的方法反映房地产价格的变化,从而提供给市场主体正确的引导信息已变得十分迫切。本文在分析了发达国家关于住房指数理论的研究成果,结合我国目前住房指数的现状及其特点的基础上,提出了一种改进的住房价格指数方案,作为对于现有上海住房指数系统的补充和完善。     

收益管理理论在电网经营企业定价中的应用

关于电网经营企业定价方法的研究，基本上都是从生产侧入手以成本为基础进行的。本文根据收益管理理论，从需求侧入手，研究了居民用户的收入与用电量的关系；研究不同收入居民用户的用电量与电价的关系；提出了计算居民用户需求价格的方法和模型；研究了企业用户的最大支付意愿，并提出了计算企业用户需求价格的计算方法和模型。     

Endogenous search,price dispersion,and welfare

This paper studies the welfare cost of inflation in a frictional monetary economy with endogenous consumer search. Equilibrium entails price dispersion, where sellers compete for buyers by posting prices. We identify three channels through which inflation affects welfare. The real balance channel is the source of welfare loss. Its interaction with the price posting channel generates a welfare cost larger than Lucas (2000). The search channel reduces the welfare cost by more than one half through general equilibrium effect. The aggregate effect of these three channels on welfare is non-monotonic. Additionally, the welfare cost of inflation fluctuations is negligible.     

A note on complete families of distributions

Some methods to establish completeness of families of distributions are discussed. Several well known parametric families are shown to be complete.     

Asymptotic properties of MLE and UMVUE in one-parameter truncated distributions

Consider one-parameter families of continuous distributions whose range depend on an unknown parameter. In case a single sufficient and complete statistic exists, we obtain the limiting distributions of MLE and UMVUE. Both distributions are different transformations of a standard exponential variable.     

R&D investment under spatial price discrimination

This paper uniquely examines an R&D rivalry under spatial price discrimination and compares two alternative timings. When firms invest first, they locate efficiently but overinvest in cost‐reducing R&D if spillover is modest. When firms locate first, they locate inefficiently and always underinvest in cost‐reducing R&D. Although the R&D investment improves social welfare under either timing, profit always declines and so it would never be undertaken if firms cooperate. Both timings are relevant as we identify circumstances under which each will endogenously be chosen in a premarket stage. Critically, the equilibrium timing is often not the socially beneficial timing.     

On truncated bivariate discrete distributions: A unified treatment

A unified treatment of three types of zero class truncation for bivariate discrete distributions is presented. Using the probability generating function approach, various properties of the truncated distributions are examined in association with the corresponding properties of the initial complete form of the distribution. Expressions for moments and conditional distributions are also obtained. Bivariate versions of the Thomas and the Intervened Poisson distributions are introduced and used as illustrative examples. Received November 2000/Revised March 2002     

Cobweb dynamics and price dispersion in illicit drug markets

Extreme price dispersion is a hallmark of illegal drug markets, and this apparent contradiction to the law of one price has long puzzled drug market economists. We propose a novel explanation for this dispersion: the coupling of dealers’ unwillingness to hold inventory with dealers’ imperfect foresight concerning future prices and/or random lead times when “ordering” drugs from higher-level suppliers. Unwillingness to hold inventory means drug markets might operate consistent with a cobweb model. The classic cobweb model was inspired by the observation of cyclic (typically annual) fluctuations in commodity prices. However, with minor changes that make the model more realistic the resulting price trajectories can be highly variable or even chaotic, not just periodic. Cobweb dynamics can also amplify the variability created by supply chain disruptions.     

Equilibrium price dynamics in an overlapping-generations exchange economy

An extension to the Yaari (1965)–Blanchard (1985) continuous time overlapping generations model for an endowment Arrow–Debreu economy with an age-structured population is presented. It is proved that Arrow–Debreu equilibrium prices are represented by a double linear integral equation, and depend on the age-distributions of population and endowments. For an economy with a balanced growth, and logarithmic utility, we prove that bubbles may exist if endowments are distributed earlier than some critical age.     

水权与城市供水价格形成机制问题探析

水权制度通过水资源管理体制决定水价形成机制.城市水问题是由不合理的水价形成机制造成的.不涉及水权制度的改革和不正确的水权观念都不可能真正完善水价形成机制.水权理论的真谛在于水权的分散化和可交易化,由此设计的以最终用户水权为基础的城市供水价格形成机制才能真正解决城市水问题.     

Optimal investment with vintage capital: Equilibrium distributions

The paper concerns the study of equilibrium points, or steady states, of economic systems arising in modeling optimal investment with vintage capital, namely, systems where all key variables (capitals, investments, prices) are indexed not only by time but also by age. Capital accumulation is hence described as a partial differential equation (briefly, PDE), and equilibrium points are in fact equilibrium distributions in the variable of ages. A general method is developed to compute and study equilibrium points of a wide range of infinite dimensional, infinite horizon, optimal control problems. We apply the method to optimal investment with vintage capital, for a variety of data, deriving existence and uniqueness of equilibrium distribution, as well as analytic formulas for optimal controls and trajectories in the long run. The examples suggest that the same method can be applied to other economic problems displaying heterogeneity. This shows how effective the theoretical machinery of optimal control in infinite dimension is in computing explicitly equilibrium distributions. To this extent, the results of this work constitute a first crucial step towards a thorough understanding of the behavior of optimal paths in the long run.     

A continuity property for local price adjustment mechanisms

This paper makes a case that a (local) continuity property is a reasonable one for any local price adjustment mechanism. This property means that if the starting points (i.e., initial prices) of the adjustment process are ‘close' to one another, and if the characteristics of the economies are ‘close' to one another, then, given any price adjustment mechanism, agents should compute equilibria that are ‘close' to one another. Under preferences which satisfy a ‘surjectivity hypothesis', it is shown that the tâtonnement process satisfies this continuity property on a nice subset of the space of all economies. A characterization of these economies for which the tâtonnement process is locally stable is given. Chart logic is a useful way to think about the path dependent property of implied volatility and about the relationship between implied volatility and historical volatility.     

Multiproduct price competition with heterogeneous consumers and nonconvex costs

This paper extends the oligopolistic model of price competition to environments with multiple goods, heterogeneous consumers, and arbitrary continuous cost functions. A Nash equilibrium in mixed strategies with an endogenous sharing rule is proven to exist. It is also shown that, in environments with fixed costs and constant marginal costs, all (symmetric and asymmetric) equilibria exhibit price dispersion across stores. Furthermore, the paper identifies scenarios in which prices will necessarily be random. In these markets, stores keep each other guessing because, given the fixed costs, they would incur a loss if their price strategies were anticipated and beaten by competitors. This is interpreted as an important economic feature that is possibly behind random price promotions such as weekly specials.     

Fractional cointegration and price discovery in Canadian commodities

Using as a unifying theme commodities important to the Canadian economy, recently developed tools are applied to studying price discovery in the spot and futures markets. For each commodity the fractionally cointegrated vector autoregression (FCVAR) model of Johansen and Neilsen is estimated and tested against the special case of the conventional cointegrated vector autoregression (CVAR). These models characterize the fundamental value of a commodity as the common stochastic trend shared by its cointegrated spot and futures prices, and so price discovery can be analyzed using the permanent-transitory decomposition of Gonzalo and Granger. Model forecasts are evaluated and compared using a distributional result due to Clark and West. The generalization to fractional cointegration is found to be statistically significant. However the economic significance of this generalization—in terms of forecast accuracy and the profitability of mean–variance dynamic trading strategies—is more fragile than may have been appreciated.     

Disclosure quality,price efficiency,and expected returns

Using a composite disclosure quality measure, we examine the effect of disclosure quality on price delay and the effect of price delay determined by disclosure quality on expected returns in the Taiwan stock market. We find that higher disclosure quality can reduce stock price delay through more investor attention and higher stock liquidity after we control for accounting quality variables and consider the endogeneity issue. Furthermore, we show that disclosure quality reduces expected stock returns through the price efficiency channel associated with both investor attention and stock liquidity. Our results indicate that increasing a firm’s standardized information rating by one standard deviation can reduce its expected stock return by 0.63% annually. Taken together, our evidence suggests that regulatory activities enforced to improve public firms’ disclosure quality in the Taiwan stock market can make the stock market more efficient and therefore lower investors’ required return for stocks.     

Optimal capital accumulation under price uncertainty and costly reversibility

We consider the optimal capital accumulation policy of a competitive firm operating in the presence of decreasing returns to scale, price uncertainty, and costly reversibility of investment. We characterize the optimal accumulation policy and derive the value of the firm by focusing on the marginal investment decision and solving the associated optimal timing problem characterizing the option value of the associated opportunity to either disinvest or acquire a marginal unit of capacity. We also characterize the required exercise premia associated with the optimal policies and demonstrate that hysteresis prevails within this class of accumulation problems as well.     

Bayesian modeling of joint and conditional distributions

In this paper, we study a Bayesian approach to flexible modeling of conditional distributions. The approach uses a flexible model for the joint distribution of the dependent and independent variables and then extracts the conditional distributions of interest from the estimated joint distribution. We use a finite mixture of multivariate normals (FMMN) to estimate the joint distribution. The conditional distributions can then be assessed analytically or through simulations. The discrete variables are handled through the use of latent variables. The estimation procedure employs an MCMC algorithm. We provide a characterization of the Kullback–Leibler closure of FMMN and show that the joint and conditional predictive densities implied by the FMMN model are consistent estimators for a large class of data generating processes with continuous and discrete observables. The method can be used as a robust regression model with discrete and continuous dependent and independent variables and as a Bayesian alternative to semi- and non-parametric models such as quantile and kernel regression. In experiments, the method compares favorably with classical nonparametric and alternative Bayesian methods.     

A statistical identity linking folded and censored distributions

This paper models expected future values of Gaussian stochastic processes that are bounded by reflecting barriers. Such expectations are of course crucial to any model with forward looking agents. The approach is illustrated by applying it to an exchange rate target zone. By adopting a distributional approach, the formal analysis can be both simple and somewhat elegant. In doing so, we show that the first moments of folded and censored distributions are related in a surprisingly neat way. The setting is discrete-time, though where appropriate we extend the analysis to the continuous-time analogue of reflected Brownian motion.