我国城乡教育不平等与收入差距扩大的动态研究

通过构造一个内生收入函数模型,利用省级面板数据,本文实证研究了我国城乡教育不平等与收入差距扩大的动态关系.研究发现:城乡教育不平等是收入差距扩大的一个重要原因,城乡教育差距第上升1%,城乡收入差距将上升6.4个百分点;并且随着市场化改革的深入,教育差距对收入差距的影响越来越重要.     

The Value of the Rent Control Option

In this paper, we combine direct arbitrage arguments and an option-pricing approach to develop a method of pricing the option for rent control. For a lump-sum payment of key money, a tenant acquires the right to rent a real estate unit for an exogenously determined controlled rent, as opposed to paying the free-market rent. The tenant may continue exercising this right as long as he or she lives. Alternatively, the tenant may sell the right to occupy the controlled rent unit and receive a fraction of the key money paid by the subsequent tenant. We value the equilibrium key money, in a representative agents partial equilibrium, while endogenously determining the expected tenure duration in a controlled rent unit. We propose a procedure for valuing rent control options different from the representative agents. Our analysis shows that under real-world levels of conditional life expectancy, the level of the fraction of the key money retained by a departing tenant has an insignificant effect on the expected tenure duration in a controlled rent unit and on the level of key money.     

Default- and call-adjusted duration for corporate bonds

Call and default can potentially alter the timing and amounts of promised cashflows for callable, corporate bonds. While prior research has indicated the theoretical importance of adjusting Macaulay duration for the impacts of default and call, the question of their relative impact remains a matter of debate [The High Yield Debt Market, Dow Jones Irwin, New York, 1990, p. 18; J. Finan. 53 (1998) 2225]. We develop a theoretical analysis incorporating both default and call effects on duration and test its implications employing a previously unexplored data base of Canadian, investment grade, corporate bond indices containing an unusual provision making it possible to identify callable and noncallable indices.     

Price Rigidity in Turkey: Evidence from Micro Data

In this study we investigate the duration of consumer price spells and price change patterns for Turkey by employing a comprehensive micro price data covering around 6,000 items over four years. In detail, we analyze how long typical price spell lasts and we investigate the size, frequency, distribution and synchronization of price changes. Compared to advanced economies, a higher frequency of price changes is estimated. Findings suggest substantial heterogeneity among sub-groups in terms of frequency and synchronization indicators. The mixed evidence of both state and time-dependent pricing is also relevant for Turkey, an emerging market economy.     

数控机床交流伺服装置

交流伺服装置是数控机床的执行环节,其性能在很大程度上影响机床进给系统的品质。本文介绍一种新的脉宽调制及自动调节的方法即把正弦波信号转换成脉冲宽度变化的调制波去驱动交流伺服电机,利用闭环系统自动调节输出交流伺服电机的电压,稳定转速,提高机床的加工精度。     

An Analysis of The Lowest Fares and Shortest Durations for Air-Tickets on Travel Agency Websites

Despite the existence of numerous published articles on website evaluations, the present tourism literature has no prior studies that examined the topics of lowest fares and shortest durations for air-tickets that are offered by travel websites. This study reports the findings of a study that investigated the practices of five online travel agency (OTA) websites. In terms of lowest airfares and the shortest in-flight durations (hereafter known as shortest durations) in four destinations for travelers who originated from Hong Kong, empirical findings showed the regional OTA outperformed other global leaders in airfares. Likewise, a smaller scale OTA offered lowest-fare air-tickets with the shortest durations. Practical implications are offered at the end of the article.     

Stochastic duration and fast coupon bond option pricing in multi-factor models

Generalizing Cox, Ingersoll, and Ross (1979), this paper defines the stochastic duration of a bond in a general multi-factor diffusion model as the time to maturity of the zero-coupon bond with the same relative volatility as the bond. Important general properties of the stochastic duration measure are derived analytically, and the stochastic duration is studied in detail in various well-known models. It is also demonstrated by analytical arguments and numerical examples that the price of a European option on a coupon bond (and, hence, of a European swaption) can be approximated very accurately by a multiple of the price of a European option on a zero-coupon bond with a time to maturity equal to the stochastic duration of the coupon bond. This revised version was published online in June 2006 with corrections to the Cover Date.     

Bond Immunization for Affine Term Structures

This paper generalizes a number of important immunization theorems. We show that the Fisher and Weil immunization, Bierwag and Khang minimax, Redington multiple liability, and Bierwag, Kaufman, and Toevs coverage theorems can be generalized to the class of affine term structures. This class of term structures contains many models that are commonly used in the finance literature.