Endogenous Random Asset Prices in Overlapping Generations Economies

This paper derives a general explicit sequential asset price process for an economy with overlapping generations of consumers. They maximize expected utility with respect to subjective transition probabilities given by Markov kernels. The process is determined primarily by the interaction of exogenous random dividends and the characteristics of consumers, given by arbitrary preferences and expectations, yielding an explicit random dynamical system with expectations feedback. The paper studies asset prices and equity premia for a parametrized class of examples with CARA utilities and exponential distributions. It provides a complete analysis of the role of risk aversion and of subjective as well as rational beliefs.     

A Microeconomic Approach to Diffusion Models For Stock Prices

This paper studies a class of diffusion models for stock prices derived by a microeconomic approach. We consider discrete-time processes resulting from a market equilibrium and then apply an invariance principle to obtain a continuous-time model. the resulting process is an Ornstein-Uhlenbeck process in a random environment, and we analyze its qualitative behavior. In particular, we provide simple criteria for the stability or instability of the corresponding stock price model, and we give explicit formulae for the invariant distributions in the recurrent case.     

EXACT SOLUTION OF A MARTINGALE STOCHASTIC VOLATILITY OPTION PROBLEM AND ITS EMPIRICAL EVALUATION

Exact explicit solution of the log-normal stochastic volatility (SV) option model has remained an open problem for two decades. In this paper, I consider the case where the risk-neutral measure induces a martingale volatility process, and derive an exact explicit solution to this unsolved problem which is also free from any inverse transforms. A representation of the asset price shows that its distribution depends on that of two random variables, the terminal SV as well as the time average of future stochastic variances. Probabilistic methods, using the author's previous results on stochastic time changes, and a Laplace–Girsanov Transform technique are applied to produce exact explicit probability distributions and option price formula. The formulae reveal interesting interplay of forces between the two random variables through the correlation coefficient. When the correlation is set to zero, the first random variable is eliminated and the option formula gives the exact formula for the limit of the Taylor series in Hull and White's (1987) approximation. The SV futures option model, comparative statics, price comparisons, the Greeks and practical and empirical implementation and evaluation results are also presented. A PC application was developed to fit the SV models to current market prices, and calculate other option prices, and their Greeks and implied volatilities (IVs) based on the results of this paper. This paper also provides a solution to the option implied volatility problem, as the empirical studies show that, the SV model can reproduce market prices, better than Black–Scholes and Black-76 by up to 2918%, and its IV curve can reproduce that of market prices very closely, by up to within its 0.37%.     

Bubbles Tomorrow and Bubbles Yesterday,but Never Bubbles Today?

Considering their importance and the amount of effort that has gone into understanding them, asset price bubbles continue to perplex. The evidence of these bubbles seldom squares with what would be expected from standard asset price theory. Unlike the suggestions from theory, expectations of prices of both stocks and houses tend to be procyclical—price expectations are driven by recent price performance. Thus, price expectations are extrapolative rather than rational, as assumed by standard asset price theory. Recognizing the role of extrapolative expectations in asset pricing will make monetary and macroprudential policy both more robust and more complex.     

Rational speculative bubbles in the gold futures market: An application of dynamic factor analysis

The existence of speculative bubbles in financial markets has been a longstanding issue under debate. Many financial economists believe that, given the assumption of rational expectations and rational behavior of economic agents, an asset should be priced according to its “market fundamentals.” Others argue that self‐fulfilling rumors of market participants can influence asset prices as well. These self‐fulfilling rumors are initiated by events extraneous to markets and are often called bubbles. The rationality of both expectations and behavior often does not imply that the price of an asset be equal to its fundamental value. In other words, there can be rational deviations of the price from this value—rational bubbles. A rational bubble can arise when the actual market price depends positively on its own expected rate of change, as normally occurs in asset markets. Since agents forming rational expectations do not make systematic prediction errors, the positive relationship between price and its expected rate of change implies a similar relationship between price and its actual rate of change. Under such conditions, the arbitrary, self‐fulfilling expectation of price changes may drive actual price changes independently of market fundamentals; we refer to such a situation as a rational price bubble.¹ © 2001 John Wiley & Sons, Inc. Jrl Fut Mark 21:79–108, 2001     

PRICE SETTING OF MARKET MAKERS: A FILTERING PROBLEM WITH ENDOGENOUS FILTRATION

This paper studies the price‐setting problem of market makers under risk neutrality and perfect competition in continuous time. The classic approach of Glosten–Milgrom is followed. Bid and ask prices are defined as conditional expectations of a true value of the asset given the market makers' partial information that includes the customers' trading decisions. The true value is modeled as a Markov process that can be observed by the customers with some noise at Poisson times. A mathematically rigorous analysis of the price‐setting problem is carried out, solving a filtering problem with endogenous filtration that depends on the bid and ask price processes quoted by the market maker. The existence and uniqueness of the bid and ask price processes is shown under some conditions.     

A Discrete Time Equivalent Martingale Measure

An equivalent martingale measure selection strategy for discrete time, continuous state, asset price evolution models is proposed. The minimal martingale law is shown to generally fail to produce a probability law in this context. The proposed strategy, termed the extended Girsanov principle, performs a multiplicative decomposition of asset price movements into a predictable and martingale component with the measure change identifying the discounted asset price process to the martingale component. However, unlike the minimal martingale law, the resulting martingale law of the extended Girsanov principle leads to weak form efficient price processes. It is shown that the proposed measure change is relevant for economies in which investors adopt hedging strategies that minimize the variance of a risk adjusted discounted cost of hedging that uses risk adjusted asset prices in calculating hedging returns. Risk adjusted prices deflate asset prices by the asset's excess return. The explicit form of the change of measure density leads to tractable econometric strategies for testing the validity of the extended Girsanov principle. A number of interesting applications of the extended Girsanov principle are also developed.     

INDIFFERENCE PRICES AND IMPLIED VOLATILITIES

We consider a general local‐stochastic volatility model and an investor with exponential utility. For a European‐style contingent claim, whose payoff may depend on either a traded or nontraded asset, we derive an explicit approximation for both the buyer's and seller's indifference prices. For European calls on a traded asset, we translate indifference prices into an explicit approximation of the buyer's and seller's implied volatility surfaces. For European claims on a nontraded asset, we establish rigorous error bounds for the indifference price approximation. Finally, we implement our indifference price and implied volatility approximations in two examples.     

我国房地产价格与通货膨胀关系的实证分析

近年来,我国房地产等资产的价格高涨所引起的“资产泡沫型通货膨胀”现象比较明显。通过观察我国近年来房屋销售价格指数和居民消费价格指数的走势发现,房地产高涨与通货膨胀之间具有很大的联动作用。因此,研究房地产价格与通货膨胀的关系,寻找破解房地产价格高涨、缓解通货膨胀压力的方法,具有重要的学术研究价值和现实意义。本文利用Granger因果关系检验模型,验证了我国房地产价格与通货膨胀关系之间存在Granger因果关系,并围绕高房价是怎样影响通货膨胀的逻辑思路,提出破解高房价、缓解“资产泡沫型通货膨胀”压力的解决方法。     

Exchange rate overshooting,the trade balance,and rational expectations

This paper presents a model of exchange-rate determination characterized by imperfect asset substitutability between domestic and foreign bonds, sticky goods-market prices, and rational expectations. The model is used to analyze the response of the exchange rate to a step change in relative money supplies. The assumption of imperfect asset substitutability permits introduction into the analysis of trade flows which respond to relative price changes. These flows create non-monotonic exchange-rate adjustments to long-run equilibrium. These non-monotonic adjustments are consistent with rationality, and may lead to short-run undershooting or overshooting.     

UTILITY MAXIMIZATION IN AN INSIDER INFLUENCED MARKET

We study a controlled stochastic system whose state is described by a stochastic differential equation with anticipating coefficients. This setting is used to model markets where insiders have some influence on the dynamics of prices. We give a characterization theorem for the optimal logarithmic portfolio of an investor with a different information flow from that of the insider. We provide explicit results in the partial information case that we extend in order to incorporate the enlargement of filtration techniques for markets with insiders. Finally, we consider a market with an insider who influences the drift of the underlying price asset process. This example gives a situation where it makes a difference for a small agent to acknowledge the existence of an insider in the market.     

汇率预期对中国通货膨胀影响的实证研究

汇率预期主要通过货币替代效应、资产价格效应和进口价格效应影响物价水平。递归VAR模型检验结果表明:2002年以来的人民币升值预期对本轮通货膨胀影响显著,其中,资产价格效应、货币替代效应、进口价格效应依次增强,影响主要集中在前期;同时,汇率预期变量对工业品出厂价格指数、消费者价格指数及货币供应量的影响都十分明显。     

APPROXIMATING GARCH-JUMP MODELS, JUMP-DIFFUSION PROCESSES, AND OPTION PRICING

This paper considers the pricing of options when there are jumps in the pricing kernel and correlated jumps in asset prices and volatilities. We extend theory developed by Nelson (1990) and Duan (1997) by considering the limiting models for our approximating GARCH Jump process. Limiting cases of our processes consist of models where both asset price and local volatility follow jump diffusion processes with correlated jump sizes. Convergence of a few GARCH models to their continuous time limits is evaluated and the benefits of the models explored.     

Idiosyncratic Risk,Borrowing Constraints and Asset Prices

This paper joins the standard consumption-based asset-pricing model (Lucas 1978) with a Bewley-type model of self-insurance (Bewley 1983) in order to analyse the interaction of systemic and idiosyncratic risk in determining the structure of asset prices. The model suggests that idiosyncratic risk affects asset prices both through a direct price effect and an indirect portfolio composition effect which may offset the price effect. The quantitative importance of these two effects is shown to depend on parameters of the model which have not previously been the focus of simulation studies.     

ON THE TIMING OPTION IN A FUTURES CONTRACT

The timing option embedded in a futures contract allows the short position to decide when to deliver the underlying asset during the last month of the contract period. In this paper we derive, within a very general incomplete market framework, an explicit model independent formula for the futures price process in the presence of a timing option. We also provide a characterization of the optimal delivery strategy, and we analyze some concrete examples.     

How long has it been since the last deal? Consumer promotion timing expectations and promotional response

When modeling consumers’ forward-looking behavior using choice data on frequently purchased products, the common approach assumes that consumers have rational expectations about future promotions. Previous studies modeled such expectations using a first-order Markov (FOM) process. However, empirical evidence from several categories suggest that inter-promotion intervals can last several weeks implying that a FOM process that conditions future expectations of prices only on current-period prices can be limiting. We utilize a Proportional Hazard model (PHM) to characterize consumers’ rational expectation of future price promotion. We first show that estimating a dynamic structural model that uses a FOM specification for rational expectations can bias estimates of promotion effects with both simulation analysis and scanner panel data from four consumer packaged goods product categories. Secondly, we empirically show that a structural model employing a PHM specification for promotion expectations fits the data better than ones that assume only a FOM price or promotion expectation. Lastly, we show using an analysis of promotion policy changes that a structural model with a FOM expectation can lead to suboptimal managerial decisions.     

Oil price shocks in a portfolio-balance model

In the 1970s oil price increases were often associated with downward pressure on the foreign exchange value of the dollar. In order to identify the factors generating this association, we examine an oil price shock in a portfolio-balance framework where a wealth transfer is generated by altered current account positions. We show that the exchange-rate impact of higher oil prices depends importantly on the asset prefernces of both oil importers and oil exporters, as well as exchange rate expectations, which are influenced by countries' abilities to adjust to higher oil prices.     

The impact of external reference price on consumer price expectations

Comparative pricing practices are frequently used where actual product prices are accompanied by higher external reference prices. All types of stores, regular-price department stores as well as discount stores, use comparative price claims to frame price deals as attractive [Marketing Science 4 (1985) 199]. In this paper, a quadratic model is specified for the impact of external reference price (ERP) on consumer price expectations. Based on the research on communication discrepancy and advertising claim discrepancy, which in turn draw on assimilation-contrast, attribution, and prospect theories, we hypothesize a quadratic effect of external reference prices on consumer price expectations. An interactive, computer-controlled experiment using multiple levels of ERP is used to estimate the proposed model. As hypothesized, support for an inverted U-shape relationship is found between consumers’ updated price expectations and the difference between ERP and initial price expectations. That is, as the difference between ERP and subjects’ initial price expectations increases, subjects’ updated price expectations increase to a point and then start to decrease. We find that the fit of the quadratic model specification for the effect of external reference price on price expectations is noticeably superior to that of linear, logarithmic, square root, and S-shaped specifications. Finally, we provide implications of our results for both retail managers and for regulatory authorities alike.     

Asset storability and price discovery in commodity futures markets: A new look

This article examines the price discovery performance of futures markets for storable and nonstorable commodities in the long run, allowing for the compounding factor of stochastic interest rates. The evidence shows that asset storability does not affect the existence of cointegration between cash and futures prices and the usefulness of future markets in predicting future cash prices. However, it may affect the magnitude of bias of futures markets’ estimates (or predictions) for future cash prices. These findings have several important implications for commodity production decision making, commodity hedging, and commodity price forecasting. © 2001 John Wiley & Sons, Inc. Jrl Fut Mark 21:279–300, 2001