ppmlhdfe: Fast Poisson Estimation with High-Dimensional Fixed Effects

In this paper we present ppmlhdfe, a new Stata command for estimation of (pseudo) Poisson regression models with multiple high-dimensional fixed effects (HDFE). Estimation is implemented using a modified version of the iteratively reweighted least-squares (IRLS) algorithm that allows for fast estimation in the presence of HDFE. Because the code is built around the reghdfe package, it has similar syntax, supports many of the same functionalities, and benefits from reghdfe's fast convergence properties for computing high-dimensional least squares problems. Performance is further enhanced by some new techniques we introduce for accelerating HDFE-IRLS estimation specifically. ppmlhdfe also implements a novel and more robust approach to check for the existence of (pseudo) maximum likelihood estimates.Comment: For associated code and data repository, see https://github.com/sergiocorreia/ppmlhdf

require: Package dependencies for reproducible research

The ability to conduct reproducible research in Stata is often limited by the lack of version control for user-submitted packages. This article introduces the require command, a tool designed to ensure Stata package dependencies are compatible across users and computer systems. Given a list of Stata packages, require verifies that each package is installed, checks for a minimum or exact version or package release date, and optionally installs the package if prompted by the researcher.Comment: for associated Git repo, see https://github.com/sergiocorreia/stata-requir

Fast Poisson Estimation with High-Dimensional Fixed Effects

In this paper we present ppmlhdfe, a new Stata command for estimation of (pseudo) Poisson regression models with multiple high-dimensional fixed effects (HDFE). Estimation is implemented using a modified version of the iteratively reweighted least-squares (IRLS) algorithm that allows for fast estimation in the presence of HDFE. Because the code is built around the reghdfe package, it has similar syntax, supports many of the same functionalities, and benefits from reghdfe’s fast convergence properties for computing high-dimensional least squares problems. Performance is further enhanced by some new techniques we introduce for accelerating HDFE-IRLS estimation specifically ppmlhdfe also implements a novel and more robust approach to check for the existence of (pseudo) maximum likelihood estimates

Pandemics Depress the Economy, Public Health Interventions Do Not: Evidence from the 1918 Flu

We study the impact of non-pharmaceutical interventions (NPIs) on mortality and economic activity across U.S. cities during the 1918 Flu Pandemic. The combination of fast and stringent NPIs reduced peak mortality by 50% and cumulative excess mortality by 24% to 34%. However, while the pandemic itself was associated with short-run economic disruptions, we find that these disruptions were similar across cities with strict and lenient NPIs. NPIs also did not worsen medium-run economic outcomes. Our findings indicate that NPIs can reduce disease transmission without further depressing economic activity, a finding also reflected in discussions in contemporary newspapers

Sistemas silvopastorales en Portugal: perspectivas para o montado, um sistema multifuncional

This lecture adresses the MOntado, its history and its role in the Portuguese landscape and also in the Portuguese agricultral sector. It raises the issue of landscape multifunctionality and how this is understaood and follwoed by land managers

Environmental niche divergence among three dune shrub sister species with parapatric distributions

Background and Aims The geographical distributions of species are constrained by their ecological requirements. The aim of this work was to analyse the effects of environmental conditions, historical events and biogeographical constraints on the diversification of the three species of the western Mediterranean shrub genus Stauracanthus, which have a parapatric distribution in the Iberian Peninsula. Methods Ecological niche factor analysis and generalized linear models were used to measure the response of all Stauracanthus species to the environmental gradients and map their potential distributions in the Iberian Peninsula. The bioclimatic niche overlap between the three species was determined by using Schoener's index. The genetic differentiation of the Iberian and northern African populations of Stauracanthus species was characterized with GenalEx. The effects on genetic distances of the most important environmental drivers were assessed through Mantel tests and non-metric multidimensional scaling. Key Results The three Stauracanthus species show remarkably similar responses to climatic conditions. This supports the idea that all members of this recently diversified clade retain common adaptations to climate and consequently high levels of climatic niche overlap. This contrasts with the diverse edaphic requirements of Stauracanthus species. The populations of the S. genistoides-spectabilis clade grow on Miocene and Pliocene fine-textured sedimentary soils, whereas S. boivinii, the more genetically distant species, occurs on older and more coarse-textured sedimentary substrates. These patterns of diversification are largely consistent with a stochastic process of geographical range expansion and fragmentation coupled with niche evolution in the context of spatially complex environmental fluctuations. Conclusions: The combined analysis of the distribution, realized environmental niche and phylogeographical relationships of parapatric species proposed in this work allows integration of the biogeographical, ecological and evolutionary processes driving the evolution of species adaptations and how they determine their current geographical ranges.FCT [UID/Multi/04326/2013, SFRH/BD/65659/2009, SFRH/BPD/85040/2012]; Portuguese FCT project COMDUNES [EXPL/BIA-BIC/2311/2013]; FCT BI grant by project COMDUNES; Atraccion de Talento Investigador Programme (Gobierno de Extremadura) [TA13032]info:eu-repo/semantics/publishedVersio

Testing the methodology to generate Design for Product Service Supportability (DfPSS) Guidelines and Rules: an application case

The industrial world is today navigating from a traditional product-based business to a new more complex solution-based orientation, pushed by new technologies, a multiple functionalities demand and a change in the customer value perception. Several are the methods and tools proposed in literature to aid manufacturers to design those solutions in an integrated and systematized way but none of them is really able to consider together product and service components, according to both company and customer views. In this context, a methodology generating new Design for X (DfX) guidelines to support the early integration of service features already in the product design of PSS has been proposed by the authors. This methodology can raise engineers’ consciousness in designing PSSs in a systematic and integrated way and provides insights into the link between the design process of PSS and the design knowledge generation in terms of guidelines and rules. In particular, the objective of this paper is to test this methodology through an application case. The test, following a theory building procedure, contributes to obtain the final methodology design, providing a double result: industrial experts’ feedbacks, giving to the authors a major awareness of its strengths and weaknesses, and new industry-specific PSS design guidelines and rules

Small rocky outcrops: natural features to promote biodiversity in oak wood‐pastures

info:eu-repo/semantics/publishedVersio

Marked object recognition multitouch screen printed touchpad for interactive applications

The market for interactive platforms is rapidly growing, and touchscreens have been incorporated in an increasing number of devices. Thus, the area of smart objects and devices is strongly increasing by adding interactive touch and multimedia content, leading to new uses and capabilities. In this work, a flexible screen printed sensor matrix is fabricated based on silver ink in a polyethylene terephthalate (PET) substrate. Diamond shaped capacitive electrodes coupled with conventional capacitive reading electronics enables fabrication of a highly functional capacitive touchpad, and also allows for the identification of marked objects. For the latter, the capacitive signatures are identified by intersecting points and distances between them. Thus, this work demonstrates the applicability of a low cost method using royalty-free geometries and technologies for the development of flexible multitouch touchpads for the implementation of interactive and object recognition applications.Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013. The authors thank the FCT for financial support under projects PTDC/EEI-SII/5582/2014 and PTDC/CTM-ENE/5387/2014. P. C., J.O. and V. C. also thank the FCT for the SFRH/BPD/110914/2015, SFRH/BPD/98219/2013 and SFRH/BPD/97739/2013 grants, respectively. Financial support from the Basque Government Industry Department under the ELKARTEK Program is also acknowledged as well as funding by theSpanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-Rinfo:eu-repo/semantics/publishedVersio