住房自有率与城市蔓延：理论与实证

通过构建一个包含住房租赁市场的封闭、单中心城市一般均衡模型，模型化了住房自有率与城市蔓延之间的关系，理论模型结论显示：首先，与自有住房者相比，租房者倾向于居住在离市中心较近的地方；其次，住房自有率的提高会使城市空间面积扩大，加剧城市蔓延。进一步，利用地级市数据分别对理论命题结论进行了检验，在比较充分地控制内生性问题后，实证结果证实了高住房自有率会加剧城市蔓延。因此，长期以来我国不断升高的住房自有率也是加剧我国城市蔓延的重要原因。     

基于最优定权组合模型的物流量预测

为了实现对市场需求变动的准确估计,在经过参阅大量文献之后,采用趋势外推模型、灰色GM（1,1）模型分别进行物流量的预测,以每种方法单项预测结果组合误差平方和最小为原则,提出一种最优定权组合预测模型,以此为物流园区的合理规划做出贡献。     

Forecasting category sales and market share for wireless telephone subscribers: a combined approach

The ability to forecast market share remains a challenge for many managers especially in dynamic markets, such as the telecommunications sector. In order to accommodate the unique dynamic characteristics of the telecommunications market, we use a multi-component model, called MSHARE. Our method involves a two-phase process. The first phase consists of three components: a projection method, a ring down survey methodology and a purchase intentions survey. The predictions from these components are combined to forecast category sales for the wireless subscribers market. In the second phase, market shares for the various brands are generated using the forecast of the number of subscribers that are obtained in Phase 1 and the share predictions from the ring down methodology. The proposed methodology produces the minimum Relative Absolute Error for each market as compared to the forecasts from each individual component in the first phase. The value of the proposed model is illustrated by its application to a real world scenario. The managerial implications of the proposed model are also discussed.     

Social networks and labor market transitions

We study the influence of social networks on labor market transitions. We develop the first model where social ties and job status coevolve through time. Our key assumption is that the probability of formation of a new tie is greater between two employed individuals than between an employed and an unemployed individual. We show that this assumption generally generates negative duration dependence of exit rates from unemployment. Our model has a number of novel testable implications. For instance, we show that a higher connectivity among unemployed individuals reduces duration dependence and that exit rates depend positively on the duration of the last job held by the unemployed worker.     

The role of interest rates during the transition to a market economy

We construct a simple two period model of an economy in transition from being centrally planned to being market oriented. Using this model, we draw certain positive conclusions about economic policies that reduce distortions during the transition period. In particular, we focus on the role of interest rates, a market parameter that has previously been almost entirely ignored in planned economies. Using stylized data derived from Czechoslovakia, we show that increase in nominal interest rates can actually be welfare-improving by partially compensating for the distortions induced by the transition process.The model is sufficiently general to be applied to a number of transition economies, and we use the cases of Czechoslovakia, the USSR, and China as examples of some of the phenomena that we are trying to explain. We show that the model generates a constrained, suboptimal equilibrium. In particular, we see that raising interest rates during the transition period reduces repressed savings, brought about by shortages in the controlled market. An improvement in consumer utility can therefore be brought about.A large part of the work in this paper was carried out while I was a Visiting Scholar in the Research Department of the International Monetary Fund. I would like to thank Mario Blejer, Nadeem Ul-Haque, and Sweder Van Wijnbergen for helpful comments. The views expressed here do not necessarily represent the opinions of the International Monetary Fund.     

我国房地产价格与宏观经济变量关系的实证分析

在对住宅服务流量模型进行修正的基础上,运用回归分析方法对我国房地产价格与宏观经济变量的长期关系进行了实证分析,研究结果表明:利率对我国房价影响较小,降息对房地产市场的刺激作用有限;房地产市场长期均衡需要人均可支配收入快速增长作保证;为控制房价稳中有降,银行应适度增加房地产信贷,但不能过度。在当前房地产市场出现"拐点"的形势下,政府要根据房地产市场的变化情况来制定相应的宏观调控政策,恢复市场信心,促进房地产市场健康发展。     

Risk sharing and counter-cyclical variation in market correlations

I present a consumption-based dynamic asset pricing model in which international market correlations vary counter-cyclically over time. The driving force in the model is the time-varying effective risk aversion induced by external habit formation. Market returns are driven by fundamental outputs and discount rates. When risk aversion is high, the effect of discount rates on market returns rises with the market price of risk. To the extent that countries share risk, the cross-country correlation of discount rates exceeds the cross-country correlation of fundamental outputs. In bad times, market correlations rise as returns are mostly driven by discount rates. Thus, consistent with the empirical evidence, periods of high risk aversion are associated with high market correlations and high market volatility. After calibration, my model is consistent with the observed variation in market correlations, as well as other features of asset prices including the equity premium and market volatility.     

基于生命周期的企业价值评估方法研究

随着中国市场经济结构不断完善和企业优化竞争速率的激增,企业价值评估的重要作用日渐凸显,企业价值评估方法封市场定价和企业价值观有着重要的导向作用。不同生命周期阶段,影响企业创造价值的因素不同,企业价值评估方法也应不同。本文依据企业生命周期理论,以现金流量模型为基础,结合企业所处的生命周期阶段,补充现金流量模型在评估企业价值时的不足之处,为企业寻找更加合理的价值评估方法。     

Understanding the determinants of crime

In this paper, we use an overlapping generations model where individuals are allowed to engage in both legitimate market activities and criminal behavior in order to assess the role of certain factors on the property crime rate. In particular, we investigate if differences in the unemployment rate, fraction of low human capital individuals in an economy, apprehension probability, duration of a jail sentence, and income inequality could be capable of generating large differences in crime rates that are observed across countries. We find that small differences in the apprehension probability and income inequality can generate quantitatively significant differences in the crime rates across similar environments.     

基于跳扩散模型的知识产权证券化定价

知识产权正不断成为资本市场上一项重要的资源。知识产权证券化作为一种新型的金融创新工具,对优化资源配置、提高金融市场效率、解决创新型中小企业融资难问题以及拓展投资渠道都起到重要的作用。为了对知识产权证券化进行合理定价,本文力求从新的视角引入跳扩散模型,将鞅论、随机微分方程理论应用到知识产权证券化的定价问题中,综合考虑违约风险与市场风险对知识产权证券化价格的影响,建立知识产权证券化定价模型,并用Monte Carlo方法对模型进行数值模拟。     

Equity Valuation and Current Cost Disclosures: the Case of Mexico

This study uses an accounting-based valuation model to investigate the relation between the market value of publicly traded Mexican firms and their disclosures of price-level adjusted accounting information. The model is estimated on a sample of Mexican companies during 1987–1990, when annual inflation rates in Mexico decreased from 130 per cent to 20 per cent. The results indicate that general price level-adjusted and current cost disclosures explain a significant portion of the cross-sectional variation in the market-to-book ratios of the sample firms. Further, the explanatory power of holding gains is robust to decreases in the general level of inflation, which suggests that current cost and constant peso disclosures are relevant for determining firm value over a wide range of inflation rates. These results are particularly important now since the Mexican Institute of CPAs has proposed eliminating the measurement of holding gains in order to make Mexican financial statements more comparable to US and Canadian GAAP.     

Model identification for infinite variance autoregressive processes

We consider model identification for infinite variance autoregressive time series processes. It is shown that a consistent estimate of autoregressive model order can be obtained by minimizing Akaike’s information criterion, and we use all-pass models to identify noncausal autoregressive processes and estimate the order of noncausality (the number of roots of the autoregressive polynomial inside the unit circle in the complex plane). We examine the performance of the order selection procedures for finite samples via simulation, and use the techniques to fit a noncausal autoregressive model to stock market trading volume data.     

基于因子分析与聚类分析复合模型的市场细分研究——以移动通信行业为例

本文从新的视角，应用因子分析与聚类分析复合模型研究市场细分和市场开拓问题。首先分析因子分析与聚类分析复合模型的应用研究现状，得出该模型在市场细分中应用的可行性。然后以移动通信行业为实证研究对象，通过设计Likert五级态度量表，对刚入校的大一学生开展抽样调查，了解新市场消费者对移动通信商及其产品的认知和态度。应用因子分析对多个观测变量进行降维，在此基础上，以公共因子和因子得分为依据，应用K—Means聚类分析法对样本进行聚类和市场细分，提出对移动通信服务商选择目标市场和进行新市场开拓的策略建议。     

Labor market entry and earnings dynamics: Bayesian inference using mixtures‐of‐experts Markov chain clustering

This paper analyzes patterns in the earnings development of young labor market entrants over their life cycle. We identify four distinctly different types of transition patterns between discrete earnings states in a large administrative dataset. Further, we investigate the effects of labor market conditions at the time of entry on the probability of belonging to each transition type. To estimate our statistical model we use a model‐based clustering approach. The statistical challenge in our application comes from the difficulty in extending distance‐based clustering approaches to the problem of identifying groups of similar time series in a panel of discrete‐valued time series. We use Markov chain clustering, which is an approach for clustering discrete‐valued time series obtained by observing a categorical variable with several states. This method is based on finite mixtures of first‐order time‐homogeneous Markov chain models. In order to analyze group membership we present an extension to this approach by formulating a probabilistic model for the latent group indicators within the Bayesian classification rule using a multinomial logit model. Copyright © 2011 John Wiley & Sons, Ltd.     

Risk aversion,public disclosure,and partially informed outsiders

In this paper, we examine the impact of public disclosure and partially informed outsiders on a risk-averse insider’s trading behavior, market efficiency, and market depth. In our model, under disclosure requirements, except for the final auction, market depth is the same at every auction. When informed outsiders are risk-neutral, in contrast to the case of a risk-averse insider with no informed outsiders, the insider is more concerned about the uncertainty about future price risk. When the number of informed outsiders increases, market liquidity improves, and the insider increases the variance of her random component to conceal her trading strategy. However, since the insider is relatively more risk-averse, she pays less attention to doing this on her own. Besides, the order flow provided by informed outsiders and randomly added by the insider injects additional liquidity into the market. When informed outsiders are risk-averse, compared to risk-neutral informed outsiders, an insider is most concerned about trading risks brought by informed outsiders at the beginning of trading. Furthermore, whether the trader is an insider or informed outsider, the more risk-averse trader has lower expected profits. Moreover, outsiders’ greater risk aversion leads to a smaller market depth.     

Renting vs buying a home: A matter of wealth accumulation or of geographic stability?

I study the housing tenure decision in the context of a spatial life cycle model with uninsurable individual income risk, plausibly calibrated to match key features of the US housing market. I find that the relatively low ownership rate of young households is mainly explained by their high geographic mobility. Downpayment constraints have minor quantitative implications on ownership rates, except for old households. I also find that idiosyncratic earnings uncertainty has a significant impact on homeownership rates. Based on these results, I argue that the long term increase in ownership rates observed over the period 1993–2009 was not necessarily due to mortgage market innovations and the relaxation of downpayment requirements, as is often argued. Instead, it was simply an implication of US demographic evolution, most notably the decline in interstate migration and, less importantly, population ageing. The model predicts that an increase in the income risk (i.e. higher income inequality) has a positive impact on geographical mobility of young households, which means that young homeowners are less affected by the labour market inefficiency associated with homeownership.     

运筹学在物流应用型人才培养中的教学模式研究

为了满足物流人才市场对物流管理人才的要求,培养物流应用型人才,探讨运筹学在物流应用型人才培养中的教学模式就变得尤为重要。文章以企业对物流人才的需求为导向,构建从教学思路、教学内容、教学程序和教学方法全方位的运筹学教学模式,并给出相应教学保障和教学评价方法。     

基于排队论的超市收费服务模型的探讨

提高顾客的通过速度,减少顾客收费的停留时间是提高超市的服务质量有效途径之一。排除论作为研究服务系统中排除现象随机规律的学科,如能将其运用于超市服务系统的规划当中,有重要的实践意义。文章根据排除论的思想建立了超市的排队服务模型。通过对模型的优化设计,科学地确定超市服务收费通道数量,并通过实例说明了该方法的计算过程,证明排队论在超市服务系统优化中具有实际用途,为类似的设计提供参考。     

虚假广告治理模式的三方博弈分析

随着我国市场经济的不断完善,广告逐渐成为消费者了解商品的性能、价格与种类的重要途径。但目前虚假广告充斥市场,部分商品经营者通过虚假广告获取超额利润,扰乱市场的正常秩序。本文利用博弈论理论,建立虚假广告主、政府及寻租者的三方博弈模型,对虚假广告的治理模式进行分析,提出了改进虚假广告治理的建议,以期能对完善虚假广告的治理模式有所启示。     

Regional Market Potential and the Number and Size of Firms: Observations and Evidence from Chile

Abstract

This paper investigates the relationship between market potential and the spatial variation in the number and the average size of firms. We adapt the canonical model of the New Economic Geography to demonstrate this relationship and to derive an empirical specification suitable for estimation through dynamic panel techniques. The model is tested against municipal data on the number of firms per adult in Chilean comunas for 2005–2010. Our results confirm that market potential along with place-specific fixed costs play an important role in determining the spatial variation in the number of firms per capita.