Migration decisions under ambiguity: Migration distance effects revisited

There is ample evidence that distance has a strong negative effect on migration. Despite its significance in migration decisions, scholars rarely explore the migration distance effect deeper than the first level of interpretation derived from the simple neoclassical theory of migration. This study revisits the migration distance effect in the spirit of Knightian distinction between risk and uncertainty. To this end, this study attempts to construct estimates of the risk premium migrants are willing to pay to avoid the risk associated with migration distance. The results show that the magnitude of the distance effect is not rationalized by risk aversion in the Arrow–Pratt sense (Arrow, 1965, The theory of risk aversion, Yrjo Jahnssonin Saatio, Helsinki, Finland, 90; Pratt, 1964, Econometrica, 32, 122). In particular, the risk premium demanded by distant rural residents is unjustifiably higher compared with that of those living closer to urban areas in their migration decisions. The results suggest that the migration distance effect is analogous to the equity home bias puzzle and the Ellsberg paradox in that the assumption of subjective expected utility can lead to seemingly irrational human behaviors. Some of the findings in this study shed light on the role of subjective aspects such as perception, confidence, and pessimism in migration decisions, which have been neglected in the literature.     

英语重复现象的语用功能

英语重复现象的功能并不局限于对某种信息的强调,还可在不同的交际环境下起不同的语用功能,具体表现为:表示同意、要求对方予以澄清、延缓作答时间、连接话题、表达激情等.     

THEORIES OF CHOICE UNDER IGNORANCE AND UNCERTAINTY

Abstract. In this paper, Knight's distinction between risk and uncertainty, and its significance for economic analysis are examined. The paper consists of a survey of some recent developments on the theory of choice under uncertainty and some applications of these theories to problems for which Bayesian Decision Theory has not proved entirely satisfactory. Two problems are examined in detail. The first is that of finance and insurance and the second is that of risktaking behaviour with special emphasis on lotteries.     

浅析语义模糊与语用模糊

国内外许多学者和研究人员对语义模糊进行了一系列比较深入的研究,而对于言语交际中存在的语用模糊现象的研究并不多见,因此对于二者的对比分析有一定的必要性。本文首先区别了语义模糊和语用模糊的概念,接着具体讨论了区分二者的方法,然后分别从谈话者和听话者角度论述了生成语义模糊和语用模糊的手段。本文的目的主要是澄清语义模糊和语用模糊的概念,并引起大家对语用模糊的更多关注。     

Completing the State Space with Subjective States

We define an opportunity act as a mapping from an exogenously given objective state space to a set of lotteries over prizes, and consider preferences over opportunity acts. We allow the preferences to be possibly uncertainty averse. Our main theorem provides an axiomatization of the maxmin expected utility model. In the theorem we construct subjective states to complete the objective state space. As in E. Dekel et al. (Econometrica, in press), we obtain a unique subjective state space. We also allow for preference for flexibility in some of the subjective states and commitment in others. Journal of Economic Literature Classification Number: D81.     

中美邀请言语行为对比研究

邀请言语行为是语言中不可缺少的部分,对于日常交际有着一定的影响;邀请言语行为与民族文化有着密切的联系,体现出不同民族的文化特色,遵循着不同的民族礼貌规范;不了解邀请言语行为的规范及其背后的民族文化,就会导致跨文化交际失误;外语教学中培养学生得体的邀请言语行为能力,可以帮助他们减少语用失误。     

The influence of risk preferences,knowledge, land consolidation,and landscape diversification on pesticide use

Researchers have spent substantial effort to identify factors influencing pesticide use intensity. However, few studies have compared the relative importance of these factors. This study examines four categories of factors that potentially influence farmers’ pesticide use decisions by evaluating incentivized experiment data, farm survey data, and remote sensing data in China. Our results suggest that land diversification has the largest effect on farmers’ pesticide use. Compared with the most rice-intensive landscape type, less rice-intensive systems cause farmers to spray less on middle rice. Heavy pesticide use intensity is associated with land fragmentation as small-scale farms still dominate crop production. Farmers’ integrated pest management knowledge has significant effects on pesticide use. We also find that loss and ambiguity preferences, rather than risk preferences, are more likely to affect pesticide use intensity.     

Policy tolerance of economic crime? An empirical analysis of the effect of counterfeiting on Italian trade

Some governments seem ambivalent towards economic crime because, on the one hand, there are adverse effects on competition and legal businesses; on the other hand, there are benefits through (shadow) employment and income in less-developed areas, as well as benefits through relations of political clientage. We focus on counterfeiting and its economic effects on trade in Italy during the economic crisis. Using a newly built regional dataset and a dynamic panel model, we find evidence of the dual impact of counterfeiting. The production (and exchange) of fake goods depresses the legal market that relies on intellectual property rights but supports shadow-economic activities for the benefit of illegal workers, criminal organisations, and political clientele. We show that the negative effects outweigh the positive effects.     

Decision-making in incomplete markets with ambiguity—a case study of a gas field acquisition

We apply utility indifference pricing to solve a contingent claim problem, valuing a connected pair of gas fields where the underlying process is not standard Geometric Brownian Motion and the assumption of complete markets is not fulfilled. First, empirical data are often characterized by time-varying volatility and fat tails; therefore, we use Gaussian generalized autoregressive score (GAS) and GARCH models, extending them to Student’s t-GARCH and t-GAS. Second, an important risk (reservoir size) is not hedgeable. As a result, markets are incomplete which makes preference free pricing impossible and thus standard option pricing methodology inapplicable. Therefore, we parametrize the investor’s risk preference and use utility indifference pricing techniques. We use Least Squares Monte Carlo simulations as a dimension reduction technique in solving the resulting stochastic dynamic programming problems. Moreover, an investor often only has an approximate idea of the true probabilistic model underlying variables, making model ambiguity a relevant problem. We show empirically how model ambiguity affects project values, and importantly, how option values change as model ambiguity gets resolved in later phases of the projects. We show that traditional valuation approaches will consistently underestimate the value of project flexibility and in general lead to overly conservative investment decisions in the presence of time-dependent stochastic structures.     

基于关联理论解读有意沉默

为了研究有意沉默在会话中的语用意义,以英汉会话语段中的有意沉默为研究对象,依据Sperber和Wilson的关联理论,从有意沉默的信息意图和交际意图,以及有意沉默的关联性与语境效果两点入手对有意沉默进行认知语用分析.对有意沉默进行认知语用解读和分析的目的在于帮助我们进一步理解有意沉默,并在以后的会话中能更好地领会并运用有意沉默,使交际能够顺利进行.