Subprime outcomes: turmoil in the mortgage market

Until 2007, few Americans had probably heard the word “subprime” - including many homeowners who would come to learn that their own mortgage was a subprime mortgage. Today, subprime mortgages are much discussed because they lie at the center of the turmoil that roiled credit markets in 2007 and 2008.Subprime mortgage

Tractrices, Bicycle Tire Tracks, Hatchet Planimeters, and a 100-year-old Conjecture

Geometry of the tracks left by a bicycle is closely related with the so-called Prytz planimeter and with linear fractional transformations of the complex plane. We describe these relations, along with the history of the problem, and give a proof of a conjecture made by Menzin in 1906.Comment: 20 pages, 18 figure

The snail-killing flies of Alaska (Diptera: Sciomyzidae)

Information is given on the geographic distribution, habitat preferences, larval foods, and immature stages for 57 species of 9 genera of Sciomyzidae known to occur in Alaska. An illustrated key to adults is included. Alaska as a habitat for sciomyzid flies is discussed, and information on feeding habits of the larvae is summarized

U. S. labor supply in the twenty-first century

The American labor force will be transformed as the twenty-first century unfolds, a change that will confront policymakers and business firms with new challenges and new opportunities. The impending slowdown of labor force growth that will accompany the retirement of the baby boom generation already is playing a central role in national debates over the future solvency of Social Security and Medicare, as well as U.S. immigration policies. But labor supply changes will be influenced by other dimensions as well. In the coming decades, American workers are likely to be, on average, older and better educated than today’s labor force. The globalization of labor markets is already opening new employment opportunities for some Americans and changing the wage rates paid to others. The production technologies and personnel policies adopted by tomorrow’s firms will undoubtedly reflect the numbers and types of workers available for employment.Labor supply ; Baby boom generation

Metacognition in the Rat

SummaryThe ability to reflect on one's own mental processes, termed metacognition, is a defining feature of human existence [1, 2]. Consequently, a fundamental question in comparative cognition is whether nonhuman animals have knowledge of their own cognitive states [3]. Recent evidence suggests that people and nonhuman primates [4–8] but not less “cognitively sophisticated” species [3, 9, 10] are capable of metacognition. Here, we demonstrate for the first time that rats are capable of metacognition—i.e., they know when they do not know the answer in a duration-discrimination test. Before taking the duration test, rats were given the opportunity to decline the test. On other trials, they were not given the option to decline the test. Accurate performance on the duration test yielded a large reward, whereas inaccurate performance resulted in no reward. Declining a test yielded a small but guaranteed reward. If rats possess knowledge regarding whether they know the answer to the test, they would be expected to decline most frequently on difficult tests and show lowest accuracy on difficult tests that cannot be declined [4]. Our data provide evidence for both predictions and suggest that a nonprimate has knowledge of its own cognitive state

Conceptualizing, Embracing, and Measuring Failure in Social Marketing Practice

Background: While failure in social marketing practice represents an emerging research agenda, the discipline has not yet considered this concept systematically or cohesively. This lack of a clear conceptualization of failure in social marketing to aid practice thus presents a significant research gap. Focus: This study aimed to conceptualize failures in social marketing practice. Methods: A qualitative survey was conducted using purposive sampling to solicit expert views of well-established social marketing academics and practitioners. Participants were asked to discuss failures in social marketing practice based on their experience in the field. A total of 49 participants provided their input to the survey. Thematic analysis was used to develop four themes addressing the research question. Importance: It is widely acknowledged that reflecting and learning from past failures to promote future best practices is desirable for any discipline. As an empirically based social change discipline, social marketing would benefit from the elevation of failure within its broader research agenda. Results: Four themes were identified: 1) Failures occur when the target behaviors are not achieved, 2) Tactics used to measure failures, 3) Process failure, and 4) Failures either not measured or reframed as lessons learned. A conceptual framework was created to characterize the nature of failures in social marketing practice, representing a feedback loop deemed problematic for the discipline. Recommendations: We call for social marketers to explicitly acknowledge and address failures when describing and reporting on their work and project outcomes. Efforts should be made to adopt a reflexive stance and examine and address internal and external factors affecting the program's failures

Depth-dependent target strengths of gadoids by the boundary-element method

Author Posting. © Acoustical Society of America, 2003. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 114 (2003): 3136-3146, doi:10.1121/1.1619982.The depth dependence of fish target strength has mostly eluded experimental investigation because of the need to distinguish it from depth-dependent behavioral effects, which may change the orientation distribution. The boundary-element method (BEM) offers an avenue of approach. Based on detailed morphometric data on 15 gadoid swimbladders, the BEM has been exercised to determine how the orientation dependence of target strength changes with pressure under the assumption that the fish swimbladder remains constant in shape and volume. The backscattering cross section has been computed at a nominal frequency of 38 kHz as a function of orientation for each of three pressures: 1, 11, and 51 atm. Increased variability in target strength and more abundant and stronger resonances are both observed with increasing depth. The respective backscattering cross sections have been averaged with respect to each of four normal distributions of tilt angle, and the corresponding target strengths have been regressed on the logarithm of fish length. The tilt-angle-averaged backscattering cross sections at the highest pressure have also been averaged with respect to frequency over a 2-kHz band for representative conditions of insonification. For all averaging methods, the mean target strength changes only slightly with depth.This work began with sponsorship by the European Commission through its RTD-program, Contract No. MAS3-CT95-0031 (BASS), and was completed with support by the Office of Naval Research, Contract No. N000140310368