A Likelihood‐Based Analysis for Relaxing the Exclusion Restriction in Randomized Experiments with Noncompliance

The exclusion restriction is usually assumed for identifying causal effects in true or only natural randomized experiments with noncompliance. It requires that the assignment to treatment does not have a direct causal effect on the outcome. Despite its importance, the restriction can often be unrealistic, especially in situations of natural experiments. It is shown that, without the exclusion restriction, the parametric model is identified if the outcome distributions of various compliance statuses are in the same parametric class and that class is a linearly independent set over the field of real numbers. However, the relaxation of the exclusion restriction yields a parametric model that is characterized by the presence of mixtures of distributions. This scenario complicates the likelihood‐based estimation procedures because it implies more than one maximum likelihood point. A two‐step estimation procedure based on detecting the root that is closest to the method of moments estimate of the parameter vector is then proposed and analyzed in detail, under normally distributed outcomes. An economic example with real data concerning returns to schooling concludes the paper.     

Sektion Soziologische Theorien

Ohne Zusammenfassung     

Society as Text: Essays on Rhetoric,Reason, and Reality,by Richard Harvey Brown

Anthropology as Cultural Critique: An Experimental Moment in the Human Sciences , by George E. Marcus and Michael M.J. Fischer.     

Choice and circumstance: Qualitative insights into contemporary childlessness in Australia

Using data from in-depth interviews with 115 women, men and couples in eastern Australia for whom family formation was a recent, current or imminent future issue, this article explores contemporary childlessness among those physically able to have children. It differentiates between those childless by choice and by circumstance, and among other themes highlights (i) the role preservation of lifestyle appears to play as a motive for deliberate childlessness following development of a life course through early adulthood that both generates lifestyle aspirations and often places parenthood on the backburner until after age 30, and (ii) the roles difficulty forming suitable relationships, women’s desire for meaningful careers, and male involvement in family formation decisions play in bringing about childlessness by circumstance.     

Business Actors in Peace Mediation Processes

Even though the relevance of business actors in peace processes is increasingly acknowledged, analysis of their particular roles and contributions remain sparse in peace mediation literature. This is despite the fact that such knowledge would be highly relevant for supporting mediation processes such as those ongoing in Colombia or the Philippines. This article looks at the involvement of business actors in mediation processes by tracing analysis along the entry points for involvement, the different roles that business actors can play and the limitations they face. The empirical data shows that business actors mainly play a role during the pre‐ and mediation phase and therein often as a support‐giver to the mediation process. Furthermore, most of the involvement does not take place at track‐1 level but rather at track‐2 mediation processes, where mainly local business play an important role. In contrary to what is postulated by some of the literature, the relevance of utilitaristic motives is not problematic; rather a monetary motivation can also foster the credibility in a political process where a lot is at stake.     

旅行家的召唤——徐霞客及其西南边陲之旅

徐霞客生前通过史无前例的、系统性与大规模的艰苦旅行,对中国八方所有的名山景观进行了考察,并因其对边陲地貌的细致考察而享有盛名。当时他选择追求自己的志趣,而没有陷入腐败政治和官僚体制的俗世纠缠,由此就像许多同时代的优秀文人一样被誉为奇人。现代知识分子反将他视为一个早期科学家的模型。通过对徐霞客西南边陲之旅的系统性考察,与明末文人"奇"和"癖"的话语相关联,由此提出,只有考虑到中国游记写作的历代仪式伦理功能,才能够更深刻地理解,为何徐霞客游记行为与思想方面的启发,远远超越了东西、古今之别,并提供了跨文化的社会更新潜力。