On preferences over subsets and the lattice structure of stable matchings

This paper studies the structure of stable multipartner matchings in two-sided markets where choice functions are quotafilling in the sense that they satisfy the substitutability axiom and, in addition, fill a quota whenever possible. It is shown that (i) the set of stable matchings is a lattice under the common revealed preference orderings of all agents on the same side, (ii) the supremum (infimum) operation of the lattice for each side consists componentwise of the join (meet) operation in the revealed preference ordering of the agents on that side, and (iii) the lattice has the polarity, distributivity, complementariness and full-quota properties. Received: 5 March 1999 / Accepted: 12 May 2000     

Political Business Cycles and Partisan Politics: Evidence from a Developing Economy

This paper explores whether the evidence supports the Political Business Cycle (PBC) theory, Partisan Theory (PT), and Rational Partisan Theory (RPT) using stock market data from Turkey, a rapidly growing developing economy. The results indicate that the PBC hypothesis is not supported by the data. We find permanent partisan effects in the conditional variance but not in returns. The conditional volatility of the returns is higher during the periods in which a leftist party or a coalition government is in office. We also find that the stock market returns temporarily decreases (increases) at the beginning of a right‐wing (left‐wing) government, providing evidence in favor of RPT.     

Credit card debt and consumption: evidence from household-level data

This research investigates the relationship between credit card debt and consumption using household level data. This is a departure from the previous studies which have used aggregate measures of consumption and general debt such as the Debt Service Ratio or total revolving credit. We use a detailed monthly survey of credit card use to impute credit card debt to respondents from the Consumer Expenditure Survey sample. In contrast to some earlier studies using aggregate data, we find a negative relationship between debt and consumption growth. Our work shows that a $1000 increase in credit card debt results in a decrease in quarterly consumption growth of almost 2%. Investigations are also made into effects of debt within different age categories and into the impact of expected income growth on the debt–consumption relationship.     

An improved model for supplier selection under capacity constraint and multiple criteria

Ghodsypour and O'Brien [2001. The total cost of logistics in supplier selection, under conditions of multiple sourcing, multiple criteria and capacity constraint. International Journal of Production Economics 73(1), 15–27] study multiple sourcing problem with multiple criteria and capacitated suppliers. Considering the buyer's quality requirements as a constraint, they develop a mixed integer non-linear programming model to find the least-cost cyclic ordering policy for the buyer. They propose to solve the model by enumerating over all possible supplier combinations. Although the problem is interesting and their analysis is correct, we point out two issues with their assumptions, namely, capacitated suppliers and cyclic ordering policy. We discuss two different capacitated supplier settings: (i) long-run average annual capacity, and (ii) exact annual capacity. First, under long-run average annual capacity assumption we propose a model which provides the same or a better solution and is much easier to solve than their model. Then, we discuss how to modify our and their models to handle exact annual capacity assumption.     

Planning perceptions and planning results

The need for planning in business organizations operating in today's complex environment is widely accepted. Implied is an assumption that planning improves performance. However, the empirical evidence for such a claim is thin. Since planning is an integral part of strategy formulation, the facts to confirm or refute an assumed connection between planning and performance invite attention. Our research focuses on new data from 61 companies which test this linkage and, in addition, reviews the conclusions of prior empirical studies.     

The impact of group-oriented values on choice of conflict management styles and outcomes: an empirical study in Turkey

Globalization has led to increased attention to cultural diversity in workforces and its influences on organizational practice. This study examines group-oriented values and their impact on choice of conflict management styles as well as on conflict resolution outcomes in Turkey. Using a sample of 315 managerial personnel from various public and private organizations, this study shows that norms of subordination of personal needs to group interests and beliefs about the effects of personal pursuit on group productivity are the most important predictors of choice of conflict management styles in Turkey. In addition, dominating and obliging styles are associated with individual profits in actual conflict resolution process and integrating style is the primary determinant of satisfaction and relationship building in conflict management. Managerial implications are then discussed on diversity and conflict management training for effective international human resources management.     

Shadow price of working in the shadows: services industry evidence

ABSTRACT

In this paper, we use an exogenous policy variation in the labour market to determine the wage gap between formally and informally employed workers. For our purposes, ‘informal employment’ describes employees who are not officially registered with any social security scheme. We use self-reported employee registration status to identify such workers, but the choice of working unregistered is not exogenous. Nevertheless, through an amnesty that was extended to only some workers in the labour market, we reduce the endogeneity problem, enabling estimation of the wage gap between these two groups. Our two-stage least square estimates reveal that the hourly wage penalty of working in the shadows is as high as 59%, and the monthly salary penalty is around 66%. Moreover, the wage gap is higher (as high as 70%) for those working in the services sector, as unregistered workers in this sector tend to be low skilled and low educated, and the monitoring of this sector is more difficult. Our analysis contributes to the literature by using an instrumental variable to treat the endogeneity of workers’ registration status. In addition, it shows that people working informally in the services industry receive a higher average wage penalty than other informally employed workers.     

Monotonicity and envyfree assignments

Summary Given any problem involving assignment of indivisible objects and a sum of money among individuals, there is an efficient envyfree allocation (namely the minmax money allocation) which can be extended monotonically to a new efficient envyfree allocation for any object added or individual removed, and another (the maximin value allocation) extendable similarly for any object removed or person added. Still, the efficient envyfree solution is largely incompatible with the resource and population monotonicity axioms: The minmax money and maxmin value allocations are unique in being extendable.I wish to thank William Thomson, David Gale, Ehud Kalai and a referee for valuable suggestions. Previous versions have appeared in the discussion paper series of CORE, Universite Catholique de Louvain, and CEME, Universite Libre de Brussels; to both of these centers I extend my thanks for the visit I enjoyed in 1992. I also gratefully acknowledge support from the Bogaziçi University Research Fund.     

THE VALUE LINE STOCK RANKINGS AND THE OPTION MODEL IMPLIED STANDARD DEVIATIONS

Here, the relationship between Value Line rankings and option implied standard deviations is investigated. Each Value Line ranking (safety, price stability, timeliness, and earnings predictability) is significantly related to option implied standard deviations for a sample of 62 companies with Value Line timeliness rankings of 1, 2, 4, and 5 and with a total of 1,217 call options traded over a 3-day period. The index for price stability would be most valuable to investors for assessing future risk since only this index has a significant association with residual implied volatility, i.e., those unexplained by historical volatility.