Mechanisms with evidence: commitment and robustness

We show that in a class of I‐agent mechanism design problems with evidence, commitment is unnecessary, randomization has no value, and robust incentive compatibility has no cost. In particular, for each agent i, we construct a simple disclosure game between the principal and agent i where the equilibrium strategies of the agents in these disclosure games give their equilibrium strategies in the game corresponding to the mechanism but where the principal is not committed to his response. In this equilibrium, the principal obtains the same payoff as in the optimal mechanism with commitment. As an application, we show that certain costly verification models can be characterized using equilibrium analysis of an associated model of evidence.Accepted manuscrip

What Will Power the Hydrogen Economy? Present and Future Sources of Hydrogen Energy

During the last ten to fifteen years advances in fuel cell technology have spurred an enormous wave of interest in hydrogen. This report first examines various methods for producing hydrogen, including discussion of the production potential for the United States. It then discusses and summarizes hydrogen distribution and delivery options, including a study of the environmental pollutant emissions implications and land and water use impacts of different production options. In addition, potential regional hydrogen production strategies around the U.S., and the potential for regional hydrogen production from renewable sources are discussed. The report concludes with a look at policy implications, particularly in light of the hydrogen production option costs and benefits that are reviewed and described in the report

A general low frequency acoustic radiation capability for NASTRAN

A new capability called NASHUA is described for calculating the radiated acoustic sound pressure field exterior to a harmonically-excited arbitrary submerged 3-D elastic structure. The surface fluid pressures and velocities are first calculated by coupling a NASTRAN finite element model of the structure with a discretized form of the Helmholtz surface integral equation for the exterior fluid. After the fluid impedance is calculated, most of the required matrix operations are performed using the general matrix manipulation package (DMAP) available in NASTRAN. Far field radiated pressures are then calculated from the surface solution using the Helmholtz exterior integral equation. Other output quantities include the maximum sound pressure levels in each of the three coordinate planes, the rms and average surface pressures and normal velocities, the total radiated power and the radiation efficiency. The overall approach is illustrated and validated using known analytic solutions for submerged spherical shells subjected to both uniform and nonuniform applied loads

Social Security Retirement Benefits Timing: A Model for Working Families

With more than 61 million individuals receiving Social Security benefits, one out of every four families in America receives monthly cash payments from the Social Security Administration (SSA). These monthly payments directly benefit 48.5 million retired workers, their current and former spouses, 10 million disabled adults, and include more than 3 million children. Several million more children and adults in the increasing number of multi-generational households in America benefit indirectly from Social Security retirement payments. In addition to the broad reach of monthly Social Security retirement benefits these payments have ensured the financial well-being of millions of American families for more than 80 years. Eight-four percent of Americans 65 and older receive benefits with more than 60 percent of Social Security beneficiaries receiving one-half or more of their income from SSA. Notably, 33 percent of all beneficiaries receive at least 90 percent of their income from SSA. The percentages of people of color who rely on Social Security income are even more significant. Hispanic, Black, and Asian seniors rely on Social Security benefits for one-half or more of their income at rates of 73, 69 and 62 percent, respectively. Similarly, Hispanic, Black, and Asian seniors rely on Social Security benefits for 90 percent or more of their income at rates of 52, 45, and 41 percent, respectively. Additionally, about 48 percent of married couples, and 71 percent of unmarried individuals, receive one-half or more of their income from SSA. After decades of decreases in defined benefit plans and interest rates, and escalating health care costs and life spans, these high rates of reliance on Social Security benefits are not surprising. Given the depth and breadth of reliance on Social Security benefits it is critical for households to understand and plan for decreasing average retirement benefit amounts. Seniors rely on Social Security retirement benefits because many have few or no other resources. According to the General Accounting Office, 41 percent of households age 55 and older; 52 percent of households age 65 through age 74; and 71 percent of households age 75 and older have no retirement savings. Therefore, maximizing Social Security retirement benefits is critical for seniors’ and their families’ health, safety, and welfare. As of June 2017, retired workers received average yearly benefits of $16,428, while surviving spouses aged 60 or older only received$15,684 of average yearly benefits. Retired workers and their spouses had average yearly aggregate benefits of $27,336, and a widowed senior with two dependent children received average yearly benefits of$31,968 for the household. These amounts represent current average earnings replacement rates of only 52, 38, 32, and 25 percent of low ($22,215), medium ($49,366), high ($78,985) and the maximum ($120,418) earnings amounts for a retired worker at age 65 in 2017. Over time these replacement rates are scheduled to decrease as full retirement age (FRA) increases. Medium earners’ replacement rates at age 65 will decrease from 38 to 34 and 31 percent in 2020 and 2030, respectively. Because Social Security benefits are such an important component of household income for families, it is not surprising that in 2016 Social Security benefits lifted more than 26 million people out of poverty including 1.5 million children, 7.5 million adults and more than 17 million seniors. Moreover, Social Security benefits decreased the depth of and proximity to poverty for millions more seniors, children, and their families. The amount of monthly Social Security retirement benefits a senior and her family receives is directly related to when they are claimed. Accordingly, the timing of claiming Social Security retirement benefits is a vital decision for individuals who rely on their benefits to support their households. Many decision models and measures being used by individuals to analyze this timing decision, among other individual financial decisions, are the same measures that have been developed to guide large business organizations. However, because of differences in economic size, capacity, life cycle, mission, goals, and unique human attributes, these large organization models do not fit the needs of lower and middle-income households. At the same time, these increasingly vulnerable individuals do need strategic measures to focus on when making financial decisions. Strategic measures specifically designed to meet the unique needs of these individuals could be valuable to their families and the economy at large as benefits are decreasing over time. One such approach is to analyze, determine, and measure the quality-value of marginal Social Security benefits to a household. This Article will present a few exemplary quality-value dollar timing models. The quality-value dollar models better expose financial advantages that seniors gain by delaying their retirement benefits. As members of Congress struggle to resolve the long-term financial viability of Social Security and Medicare given an aging and longer-living U.S. population, it is possible that increasing FRA beyond age 67 may be part of any reform package. A quality-value dollar model would be instructive in senior outreach, education, and engagement regarding Social Security benefits timing decisions and any other changes to the existing Social Security retirement system

Algorithms to automatically quantify the geometric similarity of anatomical surfaces

We describe new approaches for distances between pairs of 2-dimensional surfaces (embedded in 3-dimensional space) that use local structures and global information contained in inter-structure geometric relationships. We present algorithms to automatically determine these distances as well as geometric correspondences. This is motivated by the aspiration of students of natural science to understand the continuity of form that unites the diversity of life. At present, scientists using physical traits to study evolutionary relationships among living and extinct animals analyze data extracted from carefully defined anatomical correspondence points (landmarks). Identifying and recording these landmarks is time consuming and can be done accurately only by trained morphologists. This renders these studies inaccessible to non-morphologists, and causes phenomics to lag behind genomics in elucidating evolutionary patterns. Unlike other algorithms presented for morphological correspondences our approach does not require any preliminary marking of special features or landmarks by the user. It also differs from other seminal work in computational geometry in that our algorithms are polynomial in nature and thus faster, making pairwise comparisons feasible for significantly larger numbers of digitized surfaces. We illustrate our approach using three datasets representing teeth and different bones of primates and humans, and show that it leads to highly accurate results.Comment: Changes with respect to v1, v2: an Erratum was added, correcting the references for one of the three datasets. Note that the datasets and code for this paper can be obtained from the Data Conservancy (see Download column on v1, v2

Can Independently Elicited Adult- and Child-Perspective Health-State Utilities Explain Priority Setting?

Objectives: Time trade-off (TTO) utilities for EQ-5D-Y-3L health states valued by adults taking a child's perspective are generally higher than their valuations of the same state for themselves. Ceteris paribus, the use of these utilities in economic evaluation implies that children gain less from treatments returning them to full health for a specified amount of time than adults. In this study, we explore if this implication affects individuals’ views of priority-setting choices between treatments for adults and children. Methods: We elicited TTO utilities for 4 health states in online interviews, in which respondents valued states for a 10-year-old child and another adult their age. Views on priority setting were studied with person trade-off (PTO) tasks involving the same health states. We tested the ability of the subjects’ TTO utilities to predict these societal choices in PTO. Results: There are no significant differences between adult and child health state valuations in our study, but we do observe a substantial preference for treating children over adults in the PTO task. Conclusions: Our findings suggest that perspective-dependent health-state utilities only explain a small part of views on priority setting between adults and children. External equity weights might be useful to better explain the higher priority given to children.</p

Clostridium difficile in a farrowing pen

Clostridium difficile is an important cause of enteric disease in humans. In pigs Clostridium difficile can cause neonatal enteritis and can be isolated from faeces from diseased and healthy animals. According to recent research, isolates from humans and animals show genetic and phenotypic overlap. In The Netherlands, strains isolated from diseased piglets were indistinguishable from strains isolated from Dutch patients. These strains belonged to ribotype 078. Because pigs can either be clinical hosts and/or may be a possible reservoir more understanding of the epidemiology of Clostridium difficile among pigs is needed. The objectives of this study were to specify whether, how and when newborn piglets get infected by Clostridium difficile for the first time. With this intention, six sows, their farrowing crates and litters (71 piglets) at one farm were sampled around the day of birth of the piglets. Within 48 hours after birth, all sampled 71 piglets at the farm became positive for Clostridium difficile ribotype 078. Moreover, all sows became positive within 113 hours after birth of the piglets and the farrowing crates were intermittently positive during the sampling period. This research shows that the sow, the farrowing crate, the air and the teats of the sow are possible transmission routes of Clostridium difficile ribotype 078.This information might help to advise farmers on taking measures against Clostridium difficile infections in neonatal piglets