Stock market

Drawing on recent contributions inferring financial interconnectedness from market data, our paper provides new insights on the evolution of the US financial industry over a long period of time by using several tools coming from network science. Relying on a Time-Varying Parameter Vector AutoRegressive (TVP-VAR) approach on stock market returns to retrieve unobserved directed links among financial institutions, we reconstruct a fully dynamic network in the sense that connections are let to evolve through time...

Food waste and food insecurity are both significant issues in communities throughout the U.S., including Boulder, Colorado. As much as 40% of the food produced in the U.S. goes uneaten and ends up in landfills. Nearly 13% of people in the Boulder region experience some level of food insecurity. Founded in 2011, Boulder Food Rescue supports community members to create their own food security through a participatory approach to an emergency food system. The organization uses a web-application "robot" to manage a schedule of volunteers...

Information about a system's internal interactions is important to modeling the system's dynamics. This study examines the finer categories of the information definition and explores the features of a type of local information that describes the internal interactions of a system. Based on the results, a dual-space agent and information modeling framework (AIM) is developed by explicitly distinguishing an information space from the material space. The two spaces can evolve both independently and interactively...

Stock correlation networks use stock price data to explore the relationship between different stocks listed in the stock market. Currently this relationship is dominantly measured by the Pearson correlation coefficient. However, financial data suggest that nonlinear relationships may exist in the stock prices of different shares. To address this issue, this work uses mutual information to characterize the nonlinear relationship between stocks. Using 280 stocks traded at the Shanghai Stocks Exchange in China during the period of 2014-2016, we first compare the effectiveness of the correlation coefficient and mutual information for measuring stock relationships...

Background: Community pharmacy has been a lucrative area of practice for pharmacists in Jos, Nigeria, until about the turn of the millennium where a decline in viability of the business has been observed. Objective: This study assessed the entrepreneurial skills of community pharmacists, the business performance of community pharmacies and the impact of their entrepreneurial skills on business performance. Methods: A cross sectional survey was conducted by administering a pretested questionnaire to 30 community pharmacists in Jos...

We analyse the behaviour of a non-linear model of coupled stock and bond prices exhibiting periodically collapsing bubbles. By using the formalism of dynamical system theory, we explain what drives the bubbles and how foreshocks or aftershocks are generated. A dynamical phase space representation of that system coupled with standard multiplicative noise rationalises the log-periodic power law singularity pattern documented in many historical financial bubbles. The notion of 'ghosts of finite-time singularities' is introduced and used to estimate the end of an evolving bubble, using finite-time singularities of an approximate normal form near the bifurcation point...

We studied influence of distance to urban markets on smallholder dairy farming system development. Farms were chosen from three locations that varied in distance to the urban market of Nakuru Town in the Kenyan highlands: urban location (UL, n = 10) at less than 15 km distance, mid-rural location (MRL, n = 11) in between 20 and 50 km west of Nakuru and extreme rural location (ERL, n = 9) beyond 50 km west and south-west of Nakuru. In-depth interviews with farmers and focus group discussions with eight groups of stakeholders were held to collect narratives and data about market quality, production factors, farm performance and functions of dairy cattle...

The study was conducted to examine the management practices and constraints associated with quail production in southwestern Nigeria. Data were collected through a survey of 113 quail bird farmers selected by multi-stage sampling technique from three states of southwestern Nigeria. Data were analyzed mainly by descriptive statistics with values compared across states using relevant statistics at certain instances. The results show that quail farming is a relatively new enterprise with farmers' average year of experience estimated as 4...

Given the increasing vulnerability of communities to the negative impacts of untreated wastewater, resource recovery (RR) systems provide a paradigm shift away from a traditional approach of waste separation and treatment towards a productive recovery of water, energy and nutrients. The aim of this research is to understand the relationships between factors that influence the adoption and sustainability of wastewater-based RR systems to inform technology implementation strategies. The study presents a theory-informed, community-influenced system dynamics (SD) model to provide decision-makers with an adaptable tool that simulates system-level responses to the strategies that are developed for the coastal town of Placencia, Belize...

OBJECTIVES: The aims of this research were to determine extra-organisational challenges (e.g. market competition, governing policies) faced by community pharmacies in Sarawak, the coping strategies employed to deal with these challenges and explore potential legislative changes that can attenuate the intensity of these challenges. METHODS: Survey questionnaires (n = 184) were posted to all eligible community pharmacies in Sarawak, Malaysia. The questionnaire included sections on participants' demographic data, extra-organisational challenges faced, coping strategies employed and proposals to improve community pharmacy legislations...

The data presented in this article are related to the research article entitled "Testing and comparing the performance of dynamic variance and correlation models in value-at-risk estimation. North American Journal of Economics and Finance, 40, 116-135. doi:10.1016/j.najef.2017.02.006 (Li, 2017) [1]. Data on daily stock index return for the Canadian, UK, and US equity markets, as compiled by Morgan Stanley Capital International, are provided in this paper. The country indices comprise at least 80% of the stock market capitalization of each country...

Social media are becoming an increasingly important source of information about the public mood regarding issues such as elections, Brexit, stock market, etc. In this paper we focus on sentiment classification of Twitter data. Construction of sentiment classifiers is a standard text mining task, but here we address the question of how to properly evaluate them as there is no settled way to do so. Sentiment classes are ordered and unbalanced, and Twitter produces a stream of time-ordered data. The problem we address concerns the procedures used to obtain reliable estimates of performance measures, and whether the temporal ordering of the training and test data matters...

In this study, we assess the dynamic evolution of short-term correlation, long-term cointegration and Error Correction Model (hereafter referred to as ECM)-based long-term Granger causality between each pair of US, UK, and Eurozone stock markets from 1980 to 2015 using the rolling-window technique. A comparative analysis of pairwise dynamic integration and causality of stock markets, measured in common and domestic currency terms, is conducted to evaluate comprehensively how exchange rate fluctuations affect the time-varying integration among the S&P 500, FTSE 100 and EURO STOXX 50 indices...

BACKGROUND: Data from large electronic databases are increasingly used in epidemiological research, but golden standards for database validation remain elusive. The Prescription Registry (IPR) and the National Health Service (NHS) databases in Iceland have not undergone formal validation, and gross errors have repeatedly been found in Icelandic statistics on pharmaceuticals. In 2015, new amphetamine tablets entered the Icelandic market, but were withdrawn half a year later due to being substandard...

BACKGROUND: Since 2003 Tanzania has upgraded its approximately 7000 drug stores to Accredited Drug Dispensing Outlets (ADDOs), involving dispenser training, introduction of record keeping and enhanced regulation. Prior to accreditation, drug stores could officially stock over-the-counter medicines only, though many stocked prescription-only antimalarials. ADDOs are permitted to stock 49 prescription-only medicines, including artemisinin combination therapies and one form of quinine injectable...

Since the 2008 financial crisis, agent-based models (ABMs), which account for out-of-equilibrium dynamics, heterogeneous preferences, time horizons and strategies, have often been envisioned as the new frontier that could revolutionise and displace the more standard models and tools in economics. However, their adoption and generalisation is drastically hindered by the absence of general reliable operational calibration methods. Here, we start with a different calibration angle that qualifies an ABM for its ability to achieve abnormal trading performance with respect to the buy-and-hold strategy when fed with real financial data...

This paper introduces an original mathematical description for describing agents' decision-making process in the case of problems affected by both individual and collective behaviors in systems characterized by nonlinear, path dependent, and self-organizing interactions. An application to artificial financial markets is proposed by designing a multi-agent system based on the proposed formalization. In this application, agents' decision-making process is based on fuzzy logic rules and the price dynamics is purely deterministic according to the basic matching rules of a central order book...

How and why stock prices move is a centuries-old question still not answered conclusively. More recently, attention shifted to higher frequencies, where trades are processed piecewise across different time scales. Here we reveal that price impact has a universal nonlinear shape for trades aggregated on any intraday scale. Its shape varies little across instruments, but drastically different master curves are obtained for order-volume and -sign impact. The scaling is largely determined by the relevant Hurst exponents...

Objective In a scenario of new expensive cancer therapies entering the market, strategies of optimisation and cost containment are crucial in oncology care. Better management of drug waste and centralization of drug preparation can be effective strategies to achieve these goals. The aim of this work is to describe the economic management of a high cost anticancer drug (ipilimumab) in some Italian reference centres. Methods This was an observational, multicentred study in which economical and clinical data of 21 cancer centres (418 patients) were collected during the enrollment period from February 2013 to August 2014...

BACKGROUND: An estimated 214 million women have unmet need for family planning in developing regions. Improved utilization of the private sector is key to achieving universal access to a range of safe and effective modern contraceptive methods stipulated by FP2020 and SDG commitments. Until now, a lack of market data has limited understanding of the private sector's role in increasing contraceptive coverage and choice. METHODS: In 2015, the FPwatch Project conducted representative outlet surveys in Ethiopia, Nigeria, and DRC using a full census approach in selected administrative areas...