Clustering on the same news sources in an asset market

We study the incentives to acquire information from exclusive news sources versus information from popular sources in a CARA-normal asset market. Each trader is able to observe one of a finite number of news sources. Clustering on the most precise source can happen for two reasons. One is standard: traders do not care that they dilute others’ profits by trading on the same information. The other reason is more novel: traders with different information sets may respond to the same news differently — when this is so, they can benefit by coordinating their attention on the same news source in order to take opposite sides of the market. News from such a source will generate abnormal volume that need not be accompanied by large price movement. Furthermore, we show that as the number of sources grows, traders concentrate their attention on a few of the best ones, leaving most information unexploited.information acquisition; herding; abnormal volume; market order; limit order

Network security

In a variety of settings, some payoff-relevant item spreads along a network of connected individuals. In some cases, the item will benefit those who receive it (for example, a music download, a stock tip, news about a new research funding source, etc.) while in other cases the impact may be negative (for example, viruses, both biological and electronic, financial contagion, and so on). Often, good and bad items may propagate along the same networks, so individuals must weigh the costs and benefits of being more or less connected to the network. The situation becomes more complicated (and more interesting) if individuals can also put effort into security, where security can be thought of as a screening technology that allows an individual to keep getting the benefits of network connectivity while blocking out the bad items. Drawing on the network literatures in economics, epidemiology, and applied math, we formulate a model of network security that can be used to study individual incentives to expand and secure networks and characterize properties of a symmetric equilibrium.social networks; network security; network robustness; contagion; random graphs

Niche products, generic products, and consumer search

We endogenize product differentiation in a model of sequential search with random firm-consumer match value à la Wolinsky (1986) and Anderson and Renault (1999). We focus on a product design choice by which a firm can control the dispersion of consumer valuations for its product; we interpret low dispersion products as ‘generic’ and high dispersion products as ‘nichy.’ Equilibrium product design depends on a feedback loop: when reservation utility is high (low), the marginal customer’s match improves (worsens) with more nichy products, encouraging high (low) differentiation by firms. In turn, when firms offer more nichy products, this induces more intense search; depending on search costs, this could raise or lower consumers’ reservation utility. Remarkably, when the match distribution satisfies a hazard rate condition, firm and consumer interests align: equilibrium product design always adjusts to the level that maximizes utility. When this condition is not met, either multiple equilibria (one nichy, the other generic) or one asymmetric equilibrium (generic and nichy firms coexist) can arise; we argue that the former is more likely for common specifications of consumer preferences.product differentiation; product design; search

Procurement auctions with avoidable fixed costs: an experimental approach

Bidders in procurement auctions often face avoidable fixed costs. This can make bidding decisions complex and risky, and market outcomes volatile. If bidders deviate from risk neutral best responses, either due to faulty optimization or risk attitudes, then equilibrium predictions can perform poorly. In this paper, we confront laboratory bidders with three auction formats that make bidding difficult and risky in different ways. We find that measures of `difficulty' provide a consistent explanation of deviations from best response bidding across the three formats. In contrast, risk and loss preferences cannot explain behavior across all three formats.Auctions; Experimental; Procurement; Synergies; Asymmetric Bidders; Learning; Optimization errors

Multi-task learning method using gradient descent with applications, A

2021 Spring.Includes bibliographical references.There is a critical need to develop classification methods that can robustly and accurately classify different objects in varying environments. Each environment in a classification problem can contain its own unique challenges which prevent traditional classifiers from performing well. To solve classification problems in different environments, multi-task learning (MTL) models have been applied that define each environment as a separate task. We discuss two existing MTL algorithms and explain how they are inefficient for situations involving high-dimensional data. A gradient descent-based MTL algorithm is proposed which allows for high-dimensional data while providing accurate classification results. Additionally, we introduce a kernelized MTL algorithm which may allow us to generate nonlinear classifiers. We compared our proposed MTL method with an existing method, Efficient Lifelong Learning Algorithm (ELLA), by using them to train classifiers on the underwater unexploded ordnance (UXO) and extended modified National Institute of Standards and Technology (EMNIST) datasets. The UXO dataset contained acoustic color features of low-frequency sonar data. Both real data collected from physical experiments as well as synthetic data were used forming separate environments. The EMNIST digits dataset contains grayscale images of handwritten digits. We used this dataset to show how our proposed MTL algorithm performs when used with more tasks than are in the UXO dataset. Our classification experiments showed that our gradient descent-based algorithm resulted in improved performance over those of the traditional methods. The UXO dataset had a small improvement while the EMNIST dataset had a much larger improvement when using our MTL algorithm compared to ELLA and the single task learning method

Doctor of Philosophy

dissertationSpecific delivery of chemotherapeutic agents to cancerous tissues can potentially result in increased safety and decreased toxicity. For example, nanomedicines, including polymer-drug conjugates, can potentially accumulate in solid tumors via the "enhanced permeability and retention" (EPR) effect. Further increases in delivery can be achieved via active targeting strategies, wherein cancer-specific targeting moieties enhance cellular binding and internalization. This dissertation describes a strategy which attempts to increase the tumor accumulation and efficiency of active targeting using a combination of tumor hyperthermia and heat shock protein (HSP) targeted N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-drug conjugates. Following exposure to hyperthermia, increases in cellular stress results in initiation of the heat shock response, which includes the synthesis and migration of certain heat shock proteins to the cell surface. It is hypothesized that the induced expression of these HSPs can serve as specific molecular targets for the delivery of anticancer macromolecular chemotherapeutics. HPMA copolymer-drug conjugates bearing peptides targeting cell surface expressed glucose regulated protein 78 kDa (GRP78), a member of the HSP70 family of proteins, were synthesized, characterized, and evaluated for activity in prostate cancer models. Following exposure to hyperthermia, the cell surface expression of GRP78 was also evaluated and correlated to increases in cellular delivery and cytotoxicity of GRP78 targeted HPMA copolymeriv drug conjugates. Combination index analyses indicated that a combination of hyperthermia and HSP targeted drug therapy resulted in combined synergistic effects. In vivo, gold nanorod-mediated plasmonic photothermal therapy was utilized to induce tumor hyperthermia in a human prostate cancer animal model to enhance the delivery and efficacy of GRP78 targeted HPMA copolymer-drug conjugates. Results demonstrate that a combination of tumor hyperthermia and HSP targeting can increase tumor accumulation and cellular delivery of macromolecular chemotherapeutics, enabling safer and more effective therapies

No-Trade in the Laboratory

We test the no-trade theorem in a laboratory financial market where subjects can trade an asset whose value is unknown. Subjects receive clues on the asset value and then set a bid and an ask at which they are willing to buy or to sell from the other participants. In treatments with no gains from trade, theory predicts no trading activity, whereas, in treatments with gains, trade becomes theoretically possible. Our experimental results show that subjects fail to reach the no-trade equilibrium by pure introspection, but they learn to approach it over time,through market feedback and learning.no-trade theorem, experiment

No-Trade in the Laboratory

We test the no-trade theorem in a laboratory nancial market where subjects can trade an asset whose value is unknown. Subjects receive clues on the asset value and then set a bid and an ask at which they are willing to buy or to sell from the other participants. In treatments with no gains from trade, theory predicts no trading activity, whereas, in treatments with gains, trade becomes theoretically possible. Our experimental results show that subjects fail to reach the no-trade equilibrium by pure introspection, but they learn to approach it over time, through market feedback and learning.

“Going Back Home”: The Mawale Movement and the Rediscovery of Minahasan Identity

This paper aims to look at a cultural movement located in North Sulawesi, the Mawale Movement, seeking to refocus and rediscover Minahasan identity. Minahasa, a region in North Sulawesi, is predominantly Christian which has created an assumption that Christian identity and Minahasan identity are inseparable, or to be a Minahasan person means to be a Christian. The Mawale Movement is critically examining the idea of a Christian Minahasan identity and this paper explores the ways in which they are trying to refocus understandings of what it means to be a Minahasan person. By tracing a history of colonialism and Christianity in this area, I will introduce the Mawale Movement and examine the history, structure, and goals and missions of the movement. I will explore the ways in which Mawale tries to critically analyze this assumed Christian identity and work this rediscovered identity into Minahasan life by looking at their events and interactions with past traditions and Christianity. Ultimately, I will explore the question of what Minahasan identity is to the Mawale Movement and its importance in their lives as Minahasan people

Network security

In a variety of settings, some payoff-relevant item spreads along a network of connected individuals. In some cases, the item will benefit those who receive it (for example, a music download, a stock tip, news about a new research funding source, etc.) while in other cases the impact may be negative (for example, viruses, both biological and electronic, financial contagion, and so on). Often, good and bad items may propagate along the same networks, so individuals must weigh the costs and benefits of being more or less connected to the network. The situation becomes more complicated (and more interesting) if individuals can also put effort into security, where security can be thought of as a screening technology that allows an individual to keep getting the benefits of network connectivity while blocking out the bad items. Drawing on the network literatures in economics, epidemiology, and applied math, we formulate a model of network security that can be used to study individual incentives to expand and secure networks and characterize properties of a symmetric equilibrium