13,292 research outputs found
Clustering in Real Estate Prices: Determinants and Consequences
We examine the determinants and consequences of price clustering. Real estate list and transaction prices exhibit two price-ending characteristics: even (000-ending) and just-below-even (900-ending). The use of even-ending prices is negatively related to the precision of the price estimates and the cost of rounding. However, the tendency to use just-below-even-ending prices is related to the cost of rounding and to listing agency characteristics. The transaction price and the number of days on market are associated with list price clustering and with listing agency characteristics. Most properties are listed at just-below-even-ending prices, but those listed at even-ending prices sell faster and at a higher price. Finally, better transaction outcomes are positively associated with the number of area-properties listed by the seller?s real-estate agency.
On the nonlocal viscosity kernel of mixtures
In this report we investigate the multiscale hydrodynamical response of a
liquid as a function of mixture composition. This is done via a series of
molecular dynamics simulations where the wave vector dependent viscosity kernel
is computed for three mixtures each with 7-15 different compositions. We
observe that the nonlocal viscosity kernel is dependent on composition for
simple atomic mixtures for all the wave vectors studied here, however, for a
model polymer melt mixture the kernel is independent of composition for large
wave vectors. The deviation from ideal mixing is also studied. Here it is shown
that a Lennard-Jones mixture follows the ideal mixing rule surprisingly well
for a large range of wave vectors, whereas for both the Kob-Andersen mixture
and the polymer melt large deviations are found. Furthermore, for the polymer
melt the deviation is wave vector dependent such that there exists a critical
length scale at which the ideal mixing goes from under-estimating to
over-estimating the viscosity
Assessing proxies of knowledge and difficultywith rubric-based instruments
The fields of psychometrics, economic education, and education have developed statistically-valid methods of assessing knowledge and learning. These methods include item response theory, value-added learning models, and disaggregated learning. These methods, however, focus on multiple-choice or single response assessments. Faculty and administrators routinely assess knowledge through papers, thesis presentations, or other demonstrations of knowledge assessed with rubric rows. This paper presents a statistical approach to estimating a proxy for student ability and rubric row difficulty. Moreover, we have developed software so that practitioners can more easily apply this method to their instruments. This approach can be used in researching education treatment effects, practitioners measuring learning outcomes in their own classrooms, or estimating knowledge for administrative assessment. As an example, we have applied these new methods to projects in a large Labor Economics course at a public university
The Racial Geography of the Federal Death Penalty
Scholars have devoted substantial attention to both the overrepresentation of black defendants on federal death row and the disproportionate number of federal defendants charged capitally for the murder of white victims. This attention has not explained (much less resolved) these disquieting racial disparities. Little research has addressed the unusual geography of the federal death penalty, in which a small number of jurisdictions are responsible for the vast majority of federal death sentences. By addressing the unique geography, we identify a possible explanation for the racial distortions in the federal death penalty: that federal death sentences are sought disproportionately where the expansion of the venire from the county to the district level has a dramatic demographic impact on the racial make-up of the jury. This inquiry demonstrates that the conversation concerning who should make up the jury of twelve neighbors and peers—a discussion begun well before the founding of our Constitution—continues to have relevance today. This Article documents the historical and racial relationships between place and the ability to seat an impartial jury. We then discuss the unique impact demographic shifts in the jury pool have on death penalty decision making. Finally, we propose three possible solutions: (1) a simple, democracy-enhancing fix through a return to the historical conception of the county as the place of vicinage in federal capital trials; (2) a Batson-type three-step process for rooting out the influence of race on the decision to prosecute federally; and/or (3) voluntary measures by the Attorney General to mask demographic and location identifiers when deciding whether to provide federal death-authorization. We explain why a return to county-level jury pools in federal capital cases (whether through statutory construction, legislative change, or through the authority of a fair-minded Attorney General) prospectively limits the impact of race on the operation of the federal death penalty, without establishing the intractability of the federal death penalty as a whole. Finally, we observe that any effort to study the federal death penalty cannot merely address those federal cases in which the Attorney General has considered whether to approve an effort to seek the death penalty, but must also include an assessment of the cases prosecuted in state court that could be prosecuted federally and the prosecutorial decision concerning when and whether to prosecute in federal court
Analysis of Toxic Amyloid Fibril Interactions at Natively Derived Membranes by Ellipsometry
There is an ongoing debate regarding the culprits of cytotoxicity associated with amyloid disorders. Although small pre-fibrillar amyloid oligomers have been implicated as the primary toxic species, the fibrillar amyloid material itself can also induce cytotoxicity. To investigate membrane disruption and cytotoxic effects associated with intact and fragmented fibrils, the novel in situ spectroscopic technique of Total Internal Reflection Ellipsometry (TIRE) was used. Fibril lipid interactions were monitored using natively derived whole cell membranes as a model of the in vivo environment. We show that fragmented fibrils have an increased ability to disrupt these natively derived membranes by causing a loss of material from the deposited surface when compared with unfragmented fibrils. This effect was corroborated by observations of membrane disruption in live cells, and by dye release assay using synthetic liposomes. Through these studies we demonstrate the use of TIRE for the analysis of protein-lipid interactions on natively derived lipid surfaces, and provide an explanation on how amyloid fibrils can cause a toxic gain of function, while entangled amyloid plaques exert minimal biological activity
How Often Does Active Learning Actually Occur? Perception versus Reality
I. Measuring Active and Passive Learning There is now a robust literature touting the benefits of various active learning techniques relative to passive learning pedagogy such as lecturing (e.g., Freeman et al. 2014, Emerson and English 2016, Swoboda and Feiler 2016, Caviglia-Harris 2016). However, recent studies suggest that lecturing is still the dominant pedagogical choice in economics, even though most instructors believe that active learning methods are superior (Goffe and Kauper 2014, Watts and Schaur 2011). A limitation of these studies is that estimates of passive and active learning are based on instructors’ subjective, self-reported data
Simulating Confidence for the Ellison-Glaeser Index
The Ellison and Glaeser (1997) index is an unbiased statistic of industrial localization. Though the expected value of the index is known, ad hoc thresholds are used to interpret the extent of localization. We improve the interpretation of the index by simulating confidence intervals that a practitioner may use for a statistical test. In the data, we find cases whose index value is above the ad hoc threshold that are not statistically significant. We find many cases below the ad hoc threshold that are statistically significant. Our simulation program is freely available and is customizable for specific applications
Create random assignments: A cloud-based tool to help implement alternative teaching materials
Research has shown that learning is enhanced by variety (Bransford, Brown, and Cocking 2000; Halpern and Hakel 2003) such as popular press books, podcasts and videos. However, these mediums do not contain question banks and further, while learning management systems (LMS) can be used to generate random quizzes, they are not designed for long-form open-ended responses that might be answered over the course of a few days to weeks; open-ended questions are often ideal in upper-level undergraduate and MBA courses where there are less definitive correct answers. We solve these problems by developing software to generate assignments with randomized open-ended questions
Estimating state-industry employment, with an application to industrial localization
We describe a method to construct an industry-by-state repeated cross-section of employment at the most disaggregated level publicly available, covering 1963–2012. Nondisclosed data are estimated with a procedure using the hierarchical information structure. To illustrate the usefulness of the procedure, the resulting estimated data are tested to determine if industrial localization of the processed food sector has changed over the last 50 years in the United States. Our findings suggest it has not changed systemically despite variation in levels of localization within industries
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