Strategy-proofness in many-to-one matching problems

We search forstrategy-proof solutions in the context of (many-to-one) matching problems (Gale and Shapley, 1962). In this model, whenever the firms can hire as many workers as they want (the capacities are unlimited) the stable set is a singleton. There exists aPareto efficient, individually rational, andstrategy-proof matching rule if and only if the capacities are unlimited. Furthermore, whenever the capacities unlimited, the matching rule which selects the unique stable matching is the only matching rule that isPareto efficient, individually rational, andstrategy-proof.     

有线电视光缆传输系统指标的分析与设计

介绍了有线电视网中ＡＭ 光缆干线传输综合指标的分析与设计。由于ＤＦＢ激光器间的非线性有较大差异,故引入了光链路这一参数。当把这一参数引入有线电视光缆干线设计时,可根据有线电视光缆系统不同传输距离、光接点的分配指标和光缆干线传输系统的实际情况,计算光链路损耗,以确定光端设备的选型,从而进一步确定光缆干线传输系统的设计,使得有线电视总系统指标给以保证     

Purchasing Power Parity under Regime Shifts: An Application to Asian Countries*

This paper re‐examines the long‐run purchasing power parity (PPP) relationship for nine Asian countries relative to the USA and Japan during a period containing significant structural breaks. The relevance of considering structural breaks in PPP tests is demonstrated by utilizing the Johansen et al. (2000) procedure that allows for up to two pre‐determined structural breaks. Using conventional tests without considering breaks, one is able to reject the null of no cointegration for only four countries. The Johansen et al. procedure clearly demonstrates the importance of allowing for structural breaks and provides strong support for long‐run PPP for all the countries, regardless of the base country, except in the case of the Philippines vis‐à‐vis Japan. The Hansen–Johansen parameter constancy test indicates stability for all the countries except the Philippines relative to the USA and Malaysia relative to Japan.     

A re-examination of the forward exchange rate unbiasedness hypothesis

A Re-Examination of the Forward Exchange Rate Unbiasedness Hypothesis. — This paper applies the Phillips and Hansen estimation and inference procedures to re-examine the hypothesis that the forward exchange rate is an unbiased predictor of the future spot exchange rate. The results indicate that the 90-day forward exchange rate is not an unbiased predictor. However, the 90-day forward and future spot exchange rates are cointegrated. Only for the U.K. pound/U.S. dollar exchange rate is there an error correction representation. Overall, however, the evidence is consistent with the hypothesis that risk-averse agents in the forward foreign exchange market form expectations rationally.     

论B2C在适应性方面存在的问题

随着互联网和计算机的不断发展,电子商务已越来越受到大众的普遍关注。B2C在我国得到迅速的发展,但是在适应性方面存在的问题成为阻碍其发展的障碍。     

Bilateral Trade Balances: Evidence from Malaysia*

This study examines the impacts of real exchange rates on the bilateral trade balances of Malaysia with the USA, Japan and Singapore. The results for the long‐run cointegrating vectors show that depreciation or devaluation of real exchange rates will improve bilateral trade balances. In the short run, there is some evidence of the J‐curve phenomenon. Changes in real money supply contribute greatly to changes in real exchange rates. Generally, changes in real exchange rates contribute significantly to changes in bilateral trade balances. Monetary policy can be used to influence bilateral trade balances.     

DETERMINANTS OF INFLATION IN GHANA: AN EMPIRICAL INVESTIGATION

This paper provides an empirical analysis of the factors accounting for inflation dynamics in Ghana using the bounds test and other econometric approaches. We find that real output, nominal exchange rate, broad money supply, nominal interest rate and fiscal deficit play a dominant role in the inflationary process in Ghana. To the extent that output growth by far has the strongest impact on inflation, targeting supply‐side constraints will help moderate price inflation. The paper concludes that inflation in Ghana is explained by a combination of structural and monetary factors consistent with prior studies.     

When Do Analysts Adjust for Biases in Management Guidance? Effects of Guidance Track Record and Analysts’ Incentives

Prior research indicates that analysts do not fully adjust for the general downward bias in earnings guidance issued by management. We report the results of two experiments designed to investigate how guidance track record and analysts’ incentives jointly explain the extent to which analysts adjust for guidance bias. Our results suggest that analysts with accuracy incentives adjust for management’s track record of downwardly biased guidance when the bias is relatively small (one cent), but those with relationship incentives do not. Furthermore, the difference in adjustment is larger when the bias track record is inconsistent than when it is consistent. Also, when guidance bias is larger (two cents) relative to smaller (one cent), analysts with relationship incentives partially adjust, as they appear to strike a balance between accuracy and their desire to please management. These findings hold implications for investors, regulators, and the interpretation of prior research.     

Overbidding in fixed rate tenders: The role of exposure risk

The fixed rate tender is one of the main procedures used by central banks in the implementation of their monetary policies. While academic research has largely dismissed the procedure owing to its tendency to encourage overbidding, central banks such as the ECB and the Bank of England have continued using it. We investigate this apparent conflict by considering an auction-theoretic setting with private information about declining marginal valuations. Since overbidding entails exposure risk, an equilibrium may exist even if bids are costless and the intended volume is pre-announced. In fact, the allotment quota may be strictly below one with certainty. Also with adaptive expectations, overbidding need not escalate. However, the resulting allocation is typically inefficient. Empirical proxies of exposure risk are significant in both euro and sterling operations. Our findings have implications, in particular, for the potential reintroduction of pro rata allotment in the main refinancing operations of the Eurosystem.     

Will tighter futures price limits decrease hedge effectiveness?

The events triggered by the Global Financial Crisis (GFC) have led to calls for the regulation of financial markets. Given that regulation may involve opportunity costs, this paper examines whether tighter futures price limits can reduce the effectiveness of a futures hedge. We propose a new model that uncovers the underlying spot-futures dynamics when futures prices are subject to limits. We use the model to determine the maximum number of limit days that can occur before minimum variance hedging outcomes are adversely affected. Application of this model to the US soybean and corn markets reveals that existing limits do not reduce hedge effectiveness. If the frequency of limit days increases from current levels of 1% to approximately 3–4%, conventional hedging approaches will experience economically and statistically significant increases in portfolio variance. These results are important for hedgers, clearing houses and regulators in light of the recent calls for derivatives regulation.