Application of multi-agent games to the prediction of financial time-series

We report on a technique based on multi-agent games which has potential use in the prediction of future movements of financial time-series. A third-party game is trained on a black-box time-series, and is then run into the future to extract next-step and multi-step predictions. In addition to the possibility of identifying profit opportunities, the technique may prove useful in the development of improved risk management strategies.Comment: Work presented at the NATO Workshop on Econophysics. Prague (Feb 2001). To appear in Physica

What strategies are cost-effective in improving health care for women and their newborns?

Findings from a systematic review, conducted by Dr Lindsay Mangham-Jefferies and colleagues for the IDEAS project at the London School of Hygiene & Tropical Medicine. Funded by the Bill & Melinda Gates Foundation. Key messages: •Cost-effective strategies are needed to improve the use and provision of maternal and newborn health care, and increase the coverage of maternal and newborn health interventions. •Demand and supply-side strategies can be cost-effective, and there is strong evidence in certain contexts. •Questions remain about the extent to which both costs and effects vary by implementation, context and scale. •Evidence is limited by the number of studies on different types of demand and supply strategies and the lack of high quality studies using comparable cost-effectiveness measures. •More attention should be given to the design and reporting of cost-effectiveness studies

Evidence to improve maternal and newborn health in Ethiopia, North East Nigeria and Uttar Pradesh, India

IDEAS aims to improve the health and survival of mothers and babies through generating evidence to inform policy and practice. IDEAS uses measurement, learning and evaluation to find out what works, why and how in maternal and newborn health. IDEAS is funded between 2010 and 2015 by a grant from the Bill & Melinda Gates Foundation to the London School of Hygiene & Tropical Medicine. One research question is"Do enhanced interactions lead to increased coverage of interventions?

Dynamics of the Time Horizon Minority Game

We present exact analytic results for a new version of the Minority Game (MG) in which strategy performance is recorded over a finite time horizon. The dynamics of this Time Horizon Minority Game (THMG) exhibit many distinct features from the MG and depend strongly on whether the participants are fed real, or random, history strings. The THMG equations are equivalent to a Markov Chain, and yield exact analytic results for the volatility given a specific realization for the quenched strategy disorder.Comment: Latex file, 11 pages, 6 figure

From market games to real-world markets

This paper uses the development of multi-agent market models to present a unified approach to the joint questions of how financial market movements may be simulated, predicted, and hedged against. We examine the effect of different market clearing mechanisms and show that an out-of-equilibrium clearing process leads to dynamics that closely resemble real financial movements. We then show that replacing the `synthetic' price history used by these simulations with data taken from real financial time-series leads to the remarkable result that the agents can collectively learn to identify moments in the market where profit is attainable. We then employ the formalism of Bouchaud and Sornette in conjunction with agent based models to show that in general risk cannot be eliminated from trading with these models. We also show that, in the presence of transaction costs, the risk of option writing is greatly increased. This risk, and the costs, can however be reduced through the use of a delta-hedging strategy with modified, time-dependent volatility structure.Comment: Presented at APFA2 (Liege) July 2000. Proceedings: Eur. Phys. J. B Latex file + 10 .ps figs. [email protected]

Bush Lupine Mortality, Altered Resource Availability, and Alternative Vegetaion States

Nitrogen-fixing plants, by altering the availability of soil N, potentially facilitate plant invasion. Here we describe how herbivore-driven mortality of a native N-fixing shrub, bush lupine (Lupinus arboreus), increases soil N and light availability, which promotes invasion by introduced grasses to the detriment of a native plant community. Soils under live and dead lupine stands contained large amounts of total N, averaging 3.14 mg N/g dry mass of soil (398 g/m2) and 3.45 mg N/g dry mass of soil (438 g/m2), respectively, over four years. In contrast, similar lupine-free soil was low in N and averaged only 1.66 mg N/g dry mass of soil (211 g/m2) over three years. The addition of N fertilizer to lupine-free soil produced an 81% increase in aboveground plant biomass compared to plots unamended with N. Mean rates of net N mineralization were higher under live lupine and where mass die-off of lupine had occurred compared to soils free of bush lupine. At all sites, only 2.5–4.2% of the total soil N pool was mineralized annually. Soil enriched by lupine is not available to colonists while lupines are alive. The dense canopy of lupine shades soil under shrubs, reducing average photon-flux density in late spring from 1725 μmol·m−2·s−1 (full sunlight) to 13 μmol·m−2·s−1 (underneath shrubs). Stand die-off due to insect herbivory exposed this bare, enriched soil. In January, when annual plants are establishing, average photon-flux density under dead lupines killed by insect herbivores was 370 μmol·m−2·s−1, compared to the photon-flux density under live lupines of the same age, which averaged 83 μmol·m−2·s−1. The availability of bare, N-rich patches of soil enabled nonnative annuals (primarily Lolium multiflorum and Bromus diandrus) to colonize sites, grow rapidly, and dominate the plant assemblage until lupines reestablished after several years. The N content of these grasses was significantly greater than the N content of the mostly native plants that occupied adjacent coastal prairie devoid of bush lupine. Between 57 and 70% of the net amount of N mineralized annually was taken up by introduced grasses and subsequently returned to the soil upon the death of these annuals. Even in the absence of further N inputs, we estimate that it would take at least 25 yr to reduce the soil N pool by 50%, indicating that the reestablishment of the native prairie flora is likely to be long term

Restoring Enriched Grasslands: Effects of Mowing on Species Richness, Productivity, and Nitrogen Retention

Species-rich grasslands that become enriched with nitrogen often suffer decreases in species richness, increases in plant biomass, and invasion by weedy exotic species. Suitable techniques to restore enriched grasslands and reestablish native communities are increasingly needed. Here we report results of a 5-yr experiment in enriched coastal prairie grasslands (Bodega Marine Reserve, Bodega Bay, California, USA), to determine the combined effects of mowing and biomass removal on total soil nitrogen, net rates of mineralization, nitrogen retention, and species richness and biomass. We mowed and removed plant biomass from plots in areas where the N-fixing shrub, bush lupine (Lupinus arboreus), had greatly enriched the soil, and where the community was composed of weedy introduced plants. Our goal was to facilitate the establishment of the native grassland assemblage such as was found at nearby low soil nitrogen sites. Mowing and biomass removal resulted in a dramatic change in the species assemblage, from exotic annual grasses to a mixed exotic/native forb community composed primarily of perennials. Species richness was significantly greater in treated plots than in control plots; weedy exotic grasses diminished in abundance, and both native and exotic forb species increased. In mowed vs. control plots, there was significantly less mean aboveground biomass, but significantly greater belowground biomass. This shift in species composition had significant impacts on nitrogen retention. In late fall and winter when plant-available N was highest, much nitrogen leached from the effectively fallow control plots where germination of annual grasses did not peak until midwinter. In contrast, mowed plots retained substantially greater amounts of nitrogen, due to the presence of perennial plants possessing large amounts of belowground biomass early in the season. Despite the cumulative removal of 22 g N/m2 in biomass over 5 yr, there was no difference between mowed and control plots in total soil N, pool sizes of inorganic N, or net rates of N mineralization. The results indicate that removal of plant biomass by mowing shifted this plant community from an annual grass to a perennial forb assemblage. However, in doing so, N retention by vegetation was increased, making it more difficult to reduce soil N

Taxonomic status of diploid Salicornai europaea (s.L.) (Chenopodiaceae) in northeastern North America.

The taxonomic status of diploid Salicornia europaea L. (s.1.) in northeastern North America has been evaluated based on morphological and electrophoretic variation within and between populations. Populations of two European diploid micro- species, S. ramosissima J. Woods and S. europaea (s.s.), and populations of the midwestern diploid, S. rubra A. Nels., were also examined, affording a comparison between North American S. europaea (s.1.) and recognized species. Anther length, width of the scarious border of the fertile segment, and floral perianth shape were used to subdivide North American diploid populations into two groups. These groups were morphologically distinct from S. rubra and the European microspecies. The electrophoretic profile was unique in each morphologically distinct group of populations of S. europaea (s.1.) in northeastern North America. Based on morphological, geographical, and electrophoretic differences, diploid populations of S. europaea (s.1.) from this region are assigned to one of the following two new species: S. maririma Wolff & Jefferies, sp.nov., and S. borealis Wolff & Jefferies, sp.nov. The tetraploids are retained in S. europaea (s.1.)

Right Game, Wrong Place? A Case Study: Using a Gamified AR Application in a Heritage Context to Promote Engagement and Learning

This chapter describes an experiment in the use of gamified processes within a downloadable smartphone augmented reality (AR) application situated in a heritage context of national (UK) significance. The AR project incorporated two distinct game modes, both of which were designed to simultaneously provide users with information and motivate continued engagement. The learning gained from the AR project pertains specifically to three core threads; the first, being of fundamental importance to gamification, is that of challenge and how this links to user motivation, audience ability and prior knowledge. The second considers methodology, specifically the observation of ‘representative’ and ‘expert users’ and how a comparison of these can provide insight. The final, and most significant, thread reflects upon gamified content in relation to context, user expectation and environmental influences. The conclusion may assist others who seek to use gamification in any context by its exploration of the mistakes made and successes encountered in this case study