Dressed coordinates: the path-integrals approach

The recent introduced \textit{dressed coordinates} are studied in the path-integral approach. These coordinates are defined in the context of a harmonic oscillator linearly coupled to massless scalar field and, it is shown that in this model the dressed coordinates appear as a coordinate transformation preserving the path-integral functional measure. The analysis also generalizes the \textit{sum rules} established in a previous work.Comment: 9 pages, Latex2

Partial Identification of Local Average Treatment Effects with an Invalid Instrument

We derive nonparametric bounds for local average treatment effects without requiring the exclusion restriction assumption to hold or an outcome with a bounded support. Instead, we employ assumptions requiring weak monotonicity of mean potential outcomes within or across subpopulations defined by the values of the potential treatment status under each value of the instrument. We illustrate the identifying power of the bounds by analyzing the effect of attaining a GED, high school, or vocational degree on subsequent employment and weekly earnings using randomization into a training program as an invalid instrument.causal inference, instrumental variables, treatment effects, nonparametric bounds, principal stratification

Nonparametric Partial Identification of Causal Net and Mechanism Average Treatment Effects

When analyzing the causal e§ect of a treatment on an outcome it is important to un- derstand the mechanisms or channels through which the treatment works. In this paper we study net and mechanism average treatment e§ects (NATE and MATE, respectively), which provide an intuitive decomposition of the total average treatment e§ect (ATE) that enables learning about how the treatment a§ects the outcome. We derive informative non- parametric bounds for these two e§ects allowing for heterogeneous e§ects and without re- quiring the use of an instrumental variable or having an outcome with bounded support. We employ assumptions requiring weak monotonicity of mean potential outcomes within or across subpopulations deÖned by the potential values of the mechanism variable under each treatment arm. We illustrate the identifying power of our bounds by analyzing what part of the ATE of a training program on weekly earnings and employment is due to the obtainment of a GED, high school, or vocational degree.causal inference, treatment effects, net effects, direct effects, nonparametric bounds, principal stratification

Natalie Stoljar’s Wishful Thinking and One Step Beyond: What Should Conceptual Legal Analysis Become?

Praising wishful thinking is a serious risk that the author is willing to run not only in this article commenting of Natalie Stoljar’s work but also elsewhere in his scholarship. The author will analyze her claims and will agree mostly with them, he will also criticize her for stopping one step short adopting the desirability or weaker claim, when in it is not merely possible but necessary to go one step beyond arguing for the necessity or stronger claim. The author intends to present further grounds for endorsing “conceptual (legal) analysis pluralism” by distinguishing the three different inquiry or projects that are and must be integrated and stating the normative priority of one of them, i.e. the prescriptive, interpretive, and moral

Ronald Dworkin’s Justice for Hedgehogs and Partnership Conception of Democracy (With a Comment to Jeremy Waldron’s \u27A Majority in the Lifeboat\u27)

In this article the author focuses mainly in the last part of Ronald Dworkin´s Justice for Hedgehogs and in his argument for a partnership conception of democracy. For that purpose, first, he recalls some of the main features that Dworkin had advanced in previous but intrinsically related works, about political morality, equality and democracy; second, he reassess the arguments for a partnership conception of democracy; third, he reconsiders the resistance produced by Jeremy Waldron in his “A Majority in the Lifeboat” and the response provided by Dworkin, but since it may appear insufficient, he intends to present an alternative—or complementary—riposte in order to meet Waldron’s challenge; and, finally, he insists in the importance of taking Ronald Dworkin seriously

Reconstituting Constitutions—Institutions and Culture: The Mexican Constitution and NAFTA: Human Rights \u3ci\u3evis-à-vis\u3c/i\u3e Commerce

The aim of this Essay is threefold. First, this Essay will focus on the main characteristics of both the great transformation, experienced in the Mexican institutional economic framework during the last thirty-five years, in general, and within the past twenty years, in particular, that were made through constitutional reforms. In addition, the greater expectation that such structural reforms generated in the process of re-enacting the constitution in the political context, should be along the lines of human rights and separation of powers. Second, this Essay will attempt to bring into play the role of treaties in this transformational process, by focusing the debate on whether the North American Trade Agreement (NAFTA), as an international treaty, regardless of its denomination, is constitutional. Furthermore, this debate will concentrate the discussion on the place of treaties in the hierarchy of norms, by critically analyzing a controversial jurisprudential criteria, according to which treaties are above federal laws. Third, this Essay will illustrate that in an eventual conflict between a treaty on commerce and another treaty on human rights, the later ought to prevail over the former

Identification and Estimation of Causal Mechanisms and Net Effects of a Treatment under Unconfoundedness

An important goal when analyzing the causal effect of a treatment on an outcome is to understand the mechanisms through which the treatment causally works. We define a causal mechanism effect of a treatment and the causal effect net of that mechanism using the potential outcomes framework. These effects provide an intuitive decomposition of the total effect that is useful for policy purposes. We offer identification conditions based on an unconfoundedness assumption to estimate them, within a heterogeneous effect environment, and for the cases of a randomly assigned treatment and when selection into the treatment is based on observables. Two empirical applications illustrate the concepts and methods.causal inference, causal mechanisms, post-treatment variables, principal stratification