The Empire Struck Back: The Mexican Oil Expropriation of 1938 Reconsidered

The Mexican expropriation of 1938 was the first large-scale non-Communist expropriation of foreign-owned natural resource assets. The literature generally makes three assertions: the U.S. government did not fully back the companies, Mexico did not fully compensate them for the value of their assets, and the oil workers benefitted from the change in ownership. This paper musters data and evidence that supports only the first of those assertions, and only to a limited extent: the companies devised political strategies that maneuvered Roosevelt into supporting their interests, and they were more than fully compensated by the Mexican government as a result.

The Cost of Property Rights: Establishing Institutions on the Philippine Frontier Under American Rule, 1898-1918

We examine three reforms to property rights introduced by the United States in the Philippines in the early 20th century: the redistribution of large estates to their tenants, the creation of a system of secure land titles, and a homestead program to encourage cultivation of public lands. During the first phase of American occupation (1898-1918), we find that the implementation of these reforms was very slow. As a consequence, tenure insecurity increased over this period, and the distribution of farm sizes remained extremely unequal. We identify two primary causes for the slow progress of reform. The first was the high cost of implementing these programs, together with political constraints which prevented the government from subsidizing land reforms to a greater degree. The second was the reluctance of the government to evict delinquent or informal cultivators, especially on public lands, which reduced the costs of tenure insecurity.

Muon reconstruction and identification efficiency in ATLAS using the full Run 2 pp collision data set at \sqrt{s}=13 TeV

This article documents the muon reconstruction and identification efficiency obtained by the ATLAS experiment for 139 \hbox {fb}^{-1} of pp collision data at \sqrt{s}=13 TeV collected between 2015 and 2018 during Run 2 of the LHC. The increased instantaneous luminosity delivered by the LHC over this period required a reoptimisation of the criteria for the identification of prompt muons. Improved and newly developed algorithms were deployed to preserve high muon identification efficiency with a low misidentification rate and good momentum resolution. The availability of large samples of Z\rightarrow \mu \mu and J/\psi \rightarrow \mu \mu decays, and the minimisation of systematic uncertainties, allows the efficiencies of criteria for muon identification, primary vertex association, and isolation to be measured with an accuracy at the per-mille level in the bulk of the phase space, and up to the percent level in complex kinematic configurations. Excellent performance is achieved over a range of transverse momenta from 3 GeV to several hundred GeV, and across the full muon detector acceptance of |\eta |<2.7

Search for neutral long-lived particles in pp collisions at √s = 13 TeV that decay into displaced hadronic jets in the ATLAS calorimeter

A search for decays of pair-produced neutral long-lived particles (LLPs) is presented using 139 fb−1 of proton-proton collision data collected by the ATLAS detector at the LHC in 2015–2018 at a centre-of-mass energy of 13 TeV. Dedicated techniques were developed for the reconstruction of displaced jets produced by LLPs decaying hadronically in the ATLAS hadronic calorimeter. Two search regions are defined for different LLP kinematic regimes. The observed numbers of events are consistent with the expected background, and limits for several benchmark signals are determined. For a SM Higgs boson with a mass of 125 GeV, branching ratios above 10% are excluded at 95% confidence level for values of c times LLP mean proper lifetime in the range between 20 mm and 10 m depending on the model. Upper limits are also set on the cross-section times branching ratio for scalars with a mass of 60 GeV and for masses between 200 GeV and 1 TeV. [Figure not available: see fulltext.

Measurement of hadronic event shapes in high-p T multijet final states at √s = 13 TeV with the ATLAS detector

A measurement of event-shape variables in proton-proton collisions at large momentum transfer is presented using data collected at s = 13 TeV with the ATLAS detector at the Large Hadron Collider. Six event-shape variables calculated using hadronic jets are studied in inclusive multijet events using data corresponding to an integrated luminosity of 139 fb−1. Measurements are performed in bins of jet multiplicity and in different ranges of the scalar sum of the transverse momenta of the two leading jets, reaching scales beyond 2 TeV. These measurements are compared with predictions from Monte Carlo event generators containing leading-order or next-to-leading order matrix elements matched to parton showers simulated to leading-logarithm accuracy. At low jet multiplicities, shape discrepancies between the measurements and the Monte Carlo predictions are observed. At high jet multiplicities, the shapes are better described but discrepancies in the normalisation are observed. [Figure not available: see fulltext.