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.     

The Russian–Ukrainian earnings divide1

Ethnic differences are often considered to be powerful sources of diverse economic behaviour. In this article, we investigate to what extent ethnicity affects Ukrainian labour market outcomes. Using microdata from the Ukrainian Longitudinal Monitoring Survey and the Oaxaca–Blinder decomposition of earnings, we find a persistent and increasing labour market divide between ethnic Russians and Ukrainians throughout Ukraine’s transition era. We establish that language, rather than nationality, is the key factor behind this ethnic premium favouring Russians. Our findings further document that this premium is larger amongst males than females.     

Pricing by Arbitrage Under Arbitrary Information

A substantial applications literature on pricing by arbitrage has effectively restricted information to that arising solely from securities markets; return distributions are then governed solely by past prices. We reconsider pricing by arbitrage in markets rendered incomplete by arbitrary information, which, moreover, may influence required returns. We show that contingent claims depending solely on securities' normalized price histories are priced by arbitrage if and only if all risk-adjusted probabilities agree upon the law of primitive securities' normalized prices. We show how existing diffusion-based results can be preserved, and resolve an issue relating to Merton's (1973) stochastic interest rate model.     

Segmentation or competition in China's urban labour market?

In China, urban residents have traditionally been protectedagainst labour market competition from rural–urban migrants.Over the period of urban economic reform, rural–urbanmigration was allowed to increase in order to fill the employmentgap as growth of labour demand outstripped that of the residentlabour force in urban areas. However, as reforms gained paceand controls were lifted, it is plausible that competition forwork between migrants and urban residents would have increased.The paper examines whether the relationship is one of segmentationor competition in the labour market. It uses attitudinal responsesfrom two urban surveys. The urban workers who perceive competitionfrom migrants are those who are most vulnerable. The findingsare consistent with the presence of continued labour marketsegmentation, but suggest also that competition between thetwo groups is increasing.     

Balanced budget vs. Tax smoothing in a small open economy: A welfare comparison

The objective of this paper is to investigate the effect of lending and borrowing constraints on the dynamics of public debt and optimal taxation policy in the context of a general equilibrium model with tax smoothing. The results from the numerical simulation of the model show significant welfare gains, provided that the policymaker is allowed to borrow and lend in order to smooth taxes across time instead of maintaining a balanced budget at all times. Moreover, for a specific process for asset prices, it is also shown that if the government can issue state-contingent debt then overall welfare can be further improved substantially.     

Equilibria in incomplete assets economies with infinite dimensional spot markets

The paper studies the two period incomplete markets model where assets are claims on state contingent commodity bundles and there are no bounds on portfolio trading. The important results on the existence of equilibrium in this model assume that there is a finite number of commodities traded in each spot market and that preferences are given by smooth utility functions. With these assumptions an equilibrium exists outside an “exceptional” set of assets structures and initial endowments. The present paper extends these results by allowing for general infinite dimensional commodity spaces in each spot market. These include all the important commodity spaces studied in the literature on the existence of Walrasian equilibrium—in each spot market the consumption sets are the positive cone of an arbitrary locally solid Riesz space or of an ordered topological vector space with order unit or of a locally solid Riesz space with quasi-interior point. The paper establishes that even with our very general commodity spaces there exists an equilibrium for a “very” dense set of assets structures. Our approach is in the main convex analytic and the results do not require that preferences be smooth or complete or transitive. The concepts and techniques studied in this paper have important finite as well as infinite dimensional applications. This paper has benefited from the comments of Martine Quinzii, Wayne Shafer, Manuel Santos and Yeneng Sun. The research of C. D. Aliprantis is supported by the NSF Grants SES-0128039, DMS-0437210, and ACI-0325846. The research of R. Tourky is funded by the Australian Research Council Grant A00103450.     

绿色贸易背景下宁波中小企业拓展国际市场研究

在当前绿色贸易快速发展的背景下,绿色营销是中小企业实现资源有效配置与差异化战略并赢得一定生存空间的现实选择,也成为中小企业发展壮大的内在要求。但是宁波大多数中小企业并没有树立起科学的绿色营销观念。营销观念的演化离不开特定的制度环境与需求环境。针对绿色贸易背景下宁波中小企业的营销观念进行了剖析,并在此基础上提出了中小企业实施绿色营销拓展国际市场的对策。     

“Expiration hour effect of futures and options markets on stock market” — A case study on NSE (National Stock Exchange of India)

This paper studies the effect of expiration day of the Index futures and Options on the trading volume, variance and price of the underlying shares. The impact of derivatives trading on the underlying stock market has been widely documented in the Finance literature. In particular, significant differences in the statistical properties of asset returns (for instance, mean and variance) during expiration and non-expiration days have been advanced as an evidence for the destabilization effect (or lack there of) of derivative instruments. The earlier studies have, however, drawn their conclusions without rigorously modelling the underlying stochastic data generation process. Given that the statistical properties mentioned before are merely traits of the asset returns, this approach can lead to spurious results if analyzed in isolation of the underlying process. We propose to address this crucial shortcoming by examining the expiration day effect from a GARCH (Generalized Auto Regressive Conditional Heteroskedastic) framework. We use both daily and high frequency (5 min and 10 min) data on S&P CNX Nifty Index. Our central finding using intra-day data is that while there is no pressure – downward or upward – on index returns, the volatility is indeed significantly affected by the expiration of contracts. This effect, however, doesn’t show up in daily data.     

Slow and fast markets

Informed traders need liquidity in order to profit from their private information. Markets provide liquidity and are compensated by the information released through trading. Fast markets provide access to a limit order book. Slow markets provide execution in an auction-based trading floor. Hybrid markets combine both execution venues. It is shown here that the overall efficiency of a hybrid market is determined by its fast component. The introduction of a trading floor does not generate more informed trading, only takes trading away from the fast market. Trading floors are thus inherently competitive to the fast market. We provide conditions that determine the competitiveness of a trading floor with respect to a fast market.     

Do the urban poor face higher food prices? Evidence from Vietnam

Whether there is a poverty penalty, in terms of food prices, is unsettled in the literature after more than four decades of study. Unit values from household surveys suggest that prices vary with income while outlet surveys typically find food prices varying with store type but not with neighborhood income. Most outlet surveys are from rich countries, with just one spatially limited study from a developing country. In this paper we use especially collected food price data from metropolitan areas of Vietnam to test whether the urban poor face higher food prices. Food prices in low-income neighborhoods are 1% lower, on average, than in other neighborhoods. Unit values give a different answer to the question of whether the poor face higher prices and are not suited to answer such a question.