37 research outputs found
Estimating the employment effect of the minimum wage through variation in compliance: evidence from five US states
The implications of a binding minimum wage law on employment have been the subject of a lively and ongoing debate. Estimation of employment effects may be hindered by the non-random manner in which minimum wage laws are created. To overcome this, we explore the employment implications of the minimum wage in the US restaurant industry through an approach that exploits variation in compliance, as opposed to legislation. In the five US states without state minimum wages, violations of the US federal minimum wage are shown to be associated with decreased employment in the restaurant industry in the time period around the federal minimum wage increases of 2007 through 2009. The most robust specification shows an elasticity of employment with respect to unpaid wages of -0.233. Robustness checks use earlier time periods to show results do not reflect seasonal trends, vary the group of industries used as controls, and only use 2007 to show estimates are not confounded by a unique effect of the Great Recession on the restaurant industry
Regulation enforcement
This paper compares the effectiveness of two mechanisms of regulation enforcement: (1) the frequency of inspections and (2) penalties for violations. Threat effects of increased penalties and inspection rates, rather than corrective effects upon receiving an inspection or penalty, are the focus of analysis. Mining industry data from 2004â2009 are used to analyze the responses of mines to separate increases in inspections and citation penalties regarding regulations of safety standards. Mines did not improve safety in response to increased penalties at the ex-ante inspecting rates; however, mines significantly reduced accidents under increased inspections when implemented at those higher penalty rates. The identification strategy results in a local average treatment effect that implies increasing inspection rates from current levels would likely increase social welfare. Results are shown to be robust to bandwidth changes and model specification. The interpretation of the estimated local effect in the context of selection is analyzed. Robustness checks regarding selection exploit staffing changes and restrict to similar samples of treated and non-treated mines, justifying that results are representative
The Fiscal Transmission Mechanism of Inflation
The link between money creation and inflation has been theoretically demonstrated, but different inflation responses to Federal Reserve activity after the Great Recession and COVID recession showed the incomplete nature of the theory. We model a ``fiscal transmission mechanism'' whereby Federal Reserve purchases of Treasury securities lead to inflation as new dollars flow through fiscal deficits into the economy. In our model, other Federal Reserve activity generally lacks inflationary effects. Using a nonstructural vector autoregression approach, we test for the presence of this mechanism and offer near perfect predictions of the 2022 inflation rate using a time series extending back half a century. We explain the fiscal transmission mechanism and the reasons why other Federal Reserve activity lacks the same effects, and we propose an emphasis on controlling the money supply by limiting Federal Reserve purchases of Treasury securities as a better way to control inflation than setting an interest rate target
EUROCODE 2: BACKGROUND & APPLICATIONS DESIGN OF CONCRETE BUILDINGS Worked examples
This document is a report with worked examples presenting step-by-step the design of a reinforced concrete cast on site building following Eurocode 2. The design process has been divided between different authors, some of whom were involved in the preparation and/or assessment of Eurocode 2. Each chapter of the report focuses on a different step in the design process: conceptual design, structural analyses, limit states design and verification, detailing of the reinforcement as well as some geotechnical aspects of building design. Last chapter gives general overview of the fire design according to the Eurocodes.
The materials were prepared and presented at the workshop âEurocode 2: Design of Concrete Buildingsâ held on 20 21 October 2011 in Brussels, Belgium. The workshop was organized by JRC with the support of DG ENTR and CEN, and in collaboration with CEN/TC250/Sub-Committee 2.
The document is part of the Report Series âSupport to the implementation, harmonization and further development of the Eurocodesâ prepared by JRC in collaboration with DG ENTR and CEN/TC250 âStructural Eurocodesâ.JRC.G.5-European laboratory for structural assessmen
Conducting clinical trials in sub-Saharan Africa: challenges and lessons learned from the Malawi Cryptosporidium study
Background
An effective drug to treat cryptosporidial diarrhea in HIV-infected individuals is a global health priority. Promising drugs need to be evaluated in endemic areas which may be challenged by both lack of resources and experience to conduct International Committee of Harmonisation-Good Clinical Practice (ICH-GCP)-compliant clinical trials.
Methods
We present the challenges and lessons learned in implementing a phase 2A, randomized, double-blind, placebo-controlled trial of clofazimine, in treatment of cryptosporidiosis among HIV-infected adults at a single site in Malawi.
Results
Primary challenges are grouped under study initiation, study population, study implementation, and cultural issues. The lessons learned primarily deal with regulatory system and operational barriers, and recommendations can be applied to other human experimental trials in low- and middle-income countries, specifically in sub-Saharan Africa.
Conclusion
This study demonstrated that initiating and implementing human experimental trials in sub-Saharan Africa can be challenging. However, solutions exist and successful execution requires careful planning, ongoing evaluation, responsiveness to new developments, and oversight of all trial operations
5-Fluoro pyrimidines: labels to probe DNA and RNA secondary structures by 1D 19F NMR spectroscopy
19F NMR spectroscopy has proved to be a valuable tool to monitor functionally important conformational transitions of nucleic acids. Here, we present a systematic investigation on the application of 5-fluoro pyrimidines to probe DNA and RNA secondary structures. Oligonucleotides with the propensity to adapt secondary structure equilibria were chosen as model systems and analyzed by 1D 19F and 1H NMR spectroscopy. A comparison with the unmodified analogs revealed that the equilibrium characteristics of the bistable DNA and RNA oligonucleotides were hardly affected upon fluorine substitution at C5 of pyrimidines. This observation was in accordance with UV spectroscopic melting experiments which demonstrated that single 5-fluoro substitutions in double helices lead to comparable thermodynamic stabilities. Thus, 5-fluoro pyrimidine labeling of DNA and RNA can be reliably applied for NMR based nucleic acid secondary structure evaluation. Furthermore, we developed a facile synthetic route towards 5-fluoro cytidine phosphoramidites that enables their convenient site-specific incorporation into oligonucleotides by solid-phase synthesis
Realistic Yukawa Structures from Orientifold Compactifications
We perform a systematic analysis of globally consistent D-brane quivers which
realize the MSSM, and analyze them with respect to their Yukawa couplings.
Often, desired couplings are perturbatively forbidden due to the presence of
global U(1) symmetries. We investigate the conditions under which D-brane
instantons will induce these missing couplings without generating other
phenomenological drawbacks, such as R-parity violating couplings or a mu-term
which is too large. Furthermore, we systematically analyze which quivers allow
for a mechanism that can account for the small neutrino masses and other
experimentally observed hierarchies. We show that only a small fraction of the
globally consistent D-brane quivers exhibits phenomenology compatible with
experimental observations.Comment: 42 pages, 3 figures. v2: R-parity constraints and Yukawa texture
analysis improved; typos corrected and references adde
Mass Hierarchies from MSSM Orientifold Compactifications
We investigate phenomenologically viable four- and five-stack MSSM D-brane
quivers which exhibit realistic fermion mass hierarchies. In our analysis, the
mass hierarchies arise either from higher order terms containing the VEV's of
SM singlets or from D-instanton effects, where the latter utilizes either
family splitting or a factorizable Yukawa matrix. Extending the systematic
bottom-up analysis of arXiv:0905.3379, we present the only four-stack quiver
with a semi-realistic Yukawa texture. Investigation of five-stack MSSM models
reveals many more quivers with analogous Yukawa textures, as well as a few
examples which exhibit three different mass scales for the up-quarks,
down-quarks, and electrons. Potential problems in this class of quivers are the
presence of U(1) instantons, which might lead to undesired effects, such as
R-parity violating couplings, and the presence of dimension 5 operators that
could lead to rapid proton decay. We present a five-stack setup which overcomes
all of these problems and exhibits three different mass scales for the
up-quarks, down-quarks and electrons.Comment: 31 page
Safety and Efficacy of a Typhoid Conjugate Vaccine in Malawian Children
BACKGROUND
Typhoid fever caused by multidrug-resistant H58 Salmonella Typhi is an increasing public health threat in sub-Saharan Africa.
METHODS
We conducted a phase 3, double-blind trial in Blantyre, Malawi, to assess the efficacy of Vi polysaccharide typhoid conjugate vaccine (Vi-TCV). We randomly assigned children who were between 9 months and 12 years of age, in a 1:1 ratio, to receive a single dose of Vi-TCV or meningococcal capsular group A conjugate (MenA) vaccine. The primary outcome was typhoid fever confirmed by blood culture. We report vaccine efficacy and safety outcomes after 18 to 24 months of follow-up.
RESULTS
The intention-to-treat analysis included 28,130 children, of whom 14,069 were assigned to receive Vi-TCV and 14,061 were assigned to receive the MenA vaccine. Blood cultureâconfirmed typhoid fever occurred in 12 children in the Vi-TCV group (46.9 cases per 100,000 person-years) and in 62 children in the MenA group (243.2 cases per 100,000 person-years). Overall, the efficacy of Vi-TCV was 80.7% (95% confidence interval [CI], 64.2 to 89.6) in the intention-to-treat analysis and 83.7% (95% CI, 68.1 to 91.6) in the per-protocol analysis. In total, 130 serious adverse events occurred in the first 6 months after vaccination (52 in the Vi-TCV group and 78 in the MenA group), including 6 deaths (all in the MenA group). No serious adverse events were considered by the investigators to be related to vaccination.
CONCLUSIONS
Among Malawian children 9 months to 12 years of age, administration of Vi-TCV resulted in a lower incidence of blood cultureâconfirmed typhoid fever than the MenA vaccine. (Funded by the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT03299426
Estimating the employment effect of the minimum wage through variation in compliance: Evidence from five US states
The implications of a binding minimum wage law on employment have been the subject of a lively and ongoing debate. Estimation of employment effects may be hindered by the non-random manner in which minimum wage laws are created. To overcome this, we explore the employment implications of the minimum wage in the US restaurant industry through an approach that exploits variation in compliance, as opposed to legislation. In the five US states without state minimum wages, violations of the US federal minimum wage are shown to be associated with decreased employment in the restaurant industry in the time period around the federal minimum wage increases of 2007 through 2009. The most robust specification shows an elasticity of employment with respect to unpaid wages of -0.233. Robustness checks use earlier time periods to show results do not reflect seasonal trends, vary the group of industries used as controls, and only use 2007 to show estimates are not confounded by a unique effect of the Great Recession on the restaurant industry