前几章我们从理论上探讨了贸易政策的一般效果和政策制定。在现实中,我们发现, 不同时期人们对待国际贸易的态度和作法往往不同,甚至截然相反:即使在同一时期,不同 国家政府采取的贸易政策也有很大的差别。一般来说,贸易政策的运用会受到经济发展水平 和国际经济环境这两大因素的影响

国际贸易理论是国际经济学的微观理论部分,它以微观经济学为理论基础,解释国际贸 易的起因和影响。在正式学习国际贸易理论之前,在本章,我们首先熟悉一下国际贸易理论 的研究范围、研究方法以及所采用的一些主要分析工具

Testing for a Fractional Unit Root in Time Series Regression Chingnun Lee, Tzu-Hsiang Liao2 and Fu-Shuen Shie Inst. of Economics, National Sun Yat-sen Univ Kaohsiung, Taiwan Dept. of Finance, National Central Univ, Chung-Li, Taiwan

Ch. 9 Heteroscedasticity Regression disturbances whose variance are not constant across observations are heteroscedastic. In the heteroscedastic model we assume that

Ch.8 Nonspherical Disturbance This chapter will assume that the full ideal conditions hold except that the covari- ance matrix of the disturbance, i.e. E(EE)=02Q2, where Q is not the identity matrix. In particular, Q may be nondiagonal and / or have unequal diagonal ele- ments Two cases we shall consider in details are heteroscedasticity and auto-

Ch. 7 Violations of the ideal conditions 1 ST pecification 1.1 Selection of variables Consider a initial model. which we assume that Y=x1/1+E, It is not unusual to begin with some formulation and then contemplate adding more variable(regressors) to the model

Ch. 6 The Linear model under ideal conditions The(multiple) linear model is used to study the relationship between a dependent variable(Y) and several independent variables(X1, X2, ,Xk). That is ∫(X1,X2,…,Xk)+ E assume linear function 1X1+B2X2+…+6kXk+E xB+ where Y is the dependent or explained

Ch. 5 Hypothesis Testing The current framework of hypothesis testing is largely due to the work of Neyman and Pearson in the late 1920s, early 30s, complementing Fisher's work on estimation. As in estimation, we begin by postulating a statistical model but instead of seeking an estimator of 6 in e we consider the question whether

Ch. 4 Asymptotic Theory From the discussion of last Chapter it is obvious that determining the dis- tribution of h(X1, X2, . . Xr) is by no means a trival exercise. It turns out that more often than not we cannot determine the distribution exactly. Because of the importance of the problem, however, we are forced to develop approximations the subject of this Chapter

Ch. 3 Estimation 1 The Nature of statistical Inference It is argued that it is important to develop a mathematical model purporting to provide a generalized description of the data generating process. A prob bility model in the form of the parametric family of the density functions p=f(:0),0E e and its various ramifications formulated in last chapter