On Measures and Measurements: a Fibre Bundle approach to Contextuality

Contextuality is the failure of "local" probabilistic models to become global ones. In this paper we introduce the notions of \emph{measurable fibre bundles}, \emph{probability fibre bundles}, and \emph{sample fibre bundle} which capture and make precise the former statement. The central notions of contextuality are discussed under this formalism, examples worked out, and some new aspects pointed out.Comment: 14 pages; no figures; Purdue-Winer Memorial Lectures 2018; submitted to Phil. Trans. Roy. Soc. A. Comments are very welcom

Proposal of a two-qutrit contextuality test free of the finite precision and compatibility loopholes

It has been argued that any test of quantum contextuality is nullified by the fact that perfect orthogonality and perfect compatibility cannot be achieved in finite precision experiments. We introduce experimentally testable two-qutrit violations of inequalities for noncontextual theories in which compatibility is guaranteed by the fact that measurements are performed on separated qutrits. The inequalities are inspired by the basic building block of the Kochen-Specker proof of quantum contextuality for a qutrit, despite the fact that their proof is completely independent of it.Comment: REVTeX4-1, 5+2 pages, 1 figur

Security of Property Rights for Whom?

Recent research regarding property rights and economic development often treats property rights security in a country as homogeneous, although protecting the private entitlements of some can entail preventing others from claiming and controlling those same resources. This one-dimensional conception of property rights ignores the significant variation in the risk of expropriation faced by different groups in the same country. Using a new set of indicators that measures the property insecurity of ethnocultural minorities, this study finds that in many countries members of marginalized groups face significantly higher property insecurity than foreign investors and domestic elites, and that although secure property rights for elites and foreign investors may be positively related to long-run development, property rights for marginalized groups are not.property rights, growth, minority groups, law

Uniqueness of the joint measurement and the structure of the set of compatible quantum measurements

We address the problem of characterising the compatible tuples of measurements that admit a unique joint measurement. We derive a uniqueness criterion based on the method of perturbations and apply it to show that extremal points of the set of compatible tuples admit a unique joint measurement, while all tuples that admit a unique joint measurement lie in the boundary of such a set. We also provide counter-examples showing that none of these properties are both necessary and sufficient, thus completely describing the relation between joint measurement uniqueness and the structure of the compatible set. As a by-product of our investigations, we completely characterise the extremal and boundary points of the set of general tuples of measurements and of the subset of compatible tuples.Comment: 9 pages, 4 figures. v2, v3: minor corrections. v4: new proof of Thm. 3 and Cor. 4. The authors are thankful to Alessandro Toigo and Claudio Carmeli for pointing a flaw in the previous proof that restricted the theorem to pairs of POVM

Political Business Cycles through Lobbying

In this paper we build a framework where the interplay between the lobby power of special interest groups and the voting power of the majority of the population leads to political business cycles. We apply our set up to explain electoral cycles in government expenditure composition as well as to cycles in aggregate expenditures and in real exchange rates.

Trade and Skills in Uruguay: Long Term Skill Requirements

The paper discusses the links between skill requirements in the labour market and alternative trade patterns using a CGE applied on updated data for Uruguay. The results for alternative scenarios in the long term show that, the wage gap would widen should the pattern of trade growth follow the current trend; however, an enhanced demand of commodities would favour a reduction in the wage gap. The exercises provide insights on the economy-wide effects in the long term of the interaction of trends in trade and accumulation of skills, and thus on the role of the current policy of development of human resources.trade, skills, development