The Timing of Bid Placement and Extent of Multiple Bidding: An Empirical Investigation Using eBay Online Auctions

Online auctions are fast gaining popularity in today's electronic commerce. Relative to offline auctions, there is a greater degree of multiple bidding and late bidding in online auctions, an empirical finding by some recent research. These two behaviors (multiple bidding and late bidding) are of ``strategic'' importance to online auctions and hence important to investigate. In this article we empirically measure the distribution of bid timings and the extent of multiple bidding in a large set of online auctions, using bidder experience as a mediating variable. We use data from the popular auction site \url{www.eBay.com} to investigate more than 10,000 auctions from 15 consumer product categories. We estimate the distribution of late bidding and multiple bidding, which allows us to place these product categories along a continuum of these metrics (the extent of late bidding and the extent of multiple bidding). Interestingly, the results of the analysis distinguish most of the product categories from one another with respect to these metrics, implying that product categories, after controlling for bidder experience, differ in the extent of multiple bidding and late bidding observed in them. We also find a nonmonotonic impact of bidder experience on the timing of bid placements. Experienced bidders are ``more'' active either toward the close of auction or toward the start of auction. The impact of experience on the extent of multiple bidding, though, is monotonic across the auction interval; more experienced bidders tend to indulge ``less'' in multiple bidding.Comment: Published at http://dx.doi.org/10.1214/088342306000000123 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

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Air-Regulated Siphon Spillways: Performance, Modeling, Design, and Construction

1:Little data exists in the literature for quantification of siphon spillway performance. Proper design of an air regulated siphon spillway requires knowledge of required flow rates and minimum vent size. A set of small siphon spillways were constructed to measure flow rate and required vent size relative to physical characteristics including pipe diameter, length of pipe, and elevation head. Vent sizing was shown to be logarithmically proportional to flow rate. Results were used to develop predictive models for flow rate and vent sizing. Models were validated and refined through testing on a siphon spillway installed on a pond at LaMaster Dairy Farm in Clemson, South Carolina. 2: ABSTRACT A common problem in pond maintenance is reduced functionality of the primary spillway. Many water control structures are nearing the end of their materials\u27 life expectancy. Primary spillways constructed of corrugated metal pipe have a life expectancy of thirty years (Montana DNR, 2012). The objective of this project is to develop a set of design and construction guidelines for pond spillway rehabilitation using a siphon spillway system. This type of water control structure will be useful to landowners as an economical and reliable replacement for vertical riser spillways. To examine the application of the guidelines outlined in this chapter, a failed 40 year old water control structure at LaMaster Dairy Farm on the campus of Clemson University was replaced with a siphon spillway. The existing riser pipe rusted off about 1 m (3 ft). below its normal design elevation, resulting in an estimated loss of 1.5 ha m (16 ac ft) of water at normal elevation. Using a 2 year, 24 hour peak runoff rate from the 47.8 ha (118 ac) pond drainage area, calculations showed an 8-inch siphon would be conservatively sufficient. As a part of the guidelines developed here, Natural Resources Conservation Service (NRCS) specifications and standards are used in curve number estimation, siphon sizing and elevation, runoff calculations and emergency spillway design. Construction procedures are also reviewed in this paper. The guidelines are a tool to show the correct steps in designing and constructing a siphon spillway

An Anti-Racist Introductory Seminar Outline to Combat the Interconnectedness of Medical Racism and Maternal Morbidity and Mortality Rates Among Black Women in the United States.

Given the massive maternal morbidity and mortality crisis experienced by Black women in the United States, this thesis aims to combat one crucial aspect of this problem. Among the top eleven most developed countries in the world, the United States markedly surpasses them all as the leader in maternal mortality despite its leading advancements in biomedical technology. More specifically, the maternal mortality crisis disproportionately affects Black women in America as this population is much more likely to die of pregnancy-related causes than any other racial group in the United States. In response, researchers and organizations have published literature outlining their proposed solutions. Many of these solutions emphasize the importance of creating an education tool that will teach maternal medicine providers about the present-day impact of generational oppression, discrimination, and systemic racism that Black women are left grappling with at the expense of their own health. However, preliminary research has found that healthcare providers, regardless of specialty and level of education, are often not required to participate in training that aims to confront their own perceptions and biases that may, even if unintentionally, inform or persuade their patient care. Furthermore, this thesis will focus on creating an evidence based anti-racist introductory seminar outline that will begin the process of better informing maternal medicine healthcare providers in four key areas: the necessity of addressing implicit bias, centering the voices of Black women through their narratives of trauma, history of injustice in maternal medicine at the cost of Black female bodies, and understanding race as a social construct

Examining Evangelicalism: The Power of Signage, Painting and Sculpture in the Southern Yard Show

An analysis of self-taught artists in the American South centered on the concept of the \u27yard show.\u27 This is an in-depth examination of the manner in which evangelical rhetoric and doctrine effects signage, painting, and sculpture. This involves an exploration of the history of evangelicalism in the Southern United States, a critique of the role of the museum in self-taught art, and an analysis of missionary intentions and cults of personality surrounding work by untrained artist. Artist examined in this paper include: Howard Finster, Joe Minter, Herman Dennis, Mary Proctor, Sister Gertrude Morgan, and Nellie Mae Rowe. Thornton Dial and Lonnie Holley are featured tangentially