Game-theoretic models for mergers and acquisitions

This thesis examines the corporate merger process as a bargaining game, under the assumption that the two companies are essentially in conflict over the single issue of the price to be offered by the acquirer to the target. The first part of the thesis deals with the construction and testing of analytical game-theoretic models to explain the proportion of the synergy gains accruing to the target company under different assumptions about the players' a priori knowledge. Assuming full certainty amongst the players about the pre- and post-merger values of the companies, the distribution of gains between target and acquiring companies that would be consistent with the Nash-Kalai axioms is determined in principle. The resulting model depends on the players' utility functions, and is parameterised by the relative bargaining strength of the players and their risk aversion coefficients. An operational version of the model is fitted to empirical data from a set of 24 recent mergers of companies quoted on the Johannesburg Stock Exchange. The model is shown to have good predictive power within this data set. Under the more realistic assumption of shared uncertainty amongst the two players about the post-merger value of the combined company, a Nash-Kalai bargaining model incorporating this uncertainty is developed. This model is an improvement over those with complete certainty in that it offers improved model fit in terms of predicting the total amount paid by an acquirer, and is able to dichotomise this payment into a cash amount and a share transfer amount. The theoretical model produced some results of practical value. Firstly, a cash-only offer is never optimal. Conditions under which shares only should be tendered are identified. Secondly, the optimal offer amount depends on the form of payment and the level of perceived risk. In a share-only offer the amount is constant regardless of risk, whilst if cash is included an increase in risk will imply a decrease in the optimal amount of cash offered. The Nash-Kalai model incorporating shared uncertainty is empirically tested on the same data set used previously. This allows a comparison with earlier results and estimation of the extent of the uncertainty. An extension of this model is proposed, incorporating an alternative form of the utility functions. The second part of the thesis makes use of ideas from negotiation analysis to construct a dynamic model of the complex processes involved in negotiation. It offers prescriptive advice to one of the players on likely Pareto-optimal bargaining strategies, given a description of the strategy the other party is likely to employ. The model describes the negotiating environment and each player's negotiating strategy in terms of a few simple parameters. The model is implemented via a Monte Carlo simulation procedure, which produces expected gains to each player and average transaction values for a wide range of each of the players' strategies. The resulting two-person game bimatrix is analysed to offer general insights into negotiated outcomes, and using conventional game-theoretic and Bayesian approaches to identify "optimal" strategies for each of the players. It is shown that for the purposes of identifying optimal negotiating strategies, the players strategies (described by parameters which are continuous in nature) can be adequately approximated by a sparse grid of discrete strategies, providing that these discrete strategies are chosen so as to achieve an even spread across the set of continuous strategies. A sensitivity analysis on the contextual parameters shows that the optimal strategy pair is very robust to changes to the negotiating environment, and any such changes that have the players start negotiating from positions more removed from one another is more detrimental to the target. A conceptual decision support system which uses the model and simulated results as key components is proposed and outlined

A mathematical approach to the evaluation of international diversification for the South African investor

This thesis attempts to isolate the major markets for investment outside South Africa, and to determine what proportion of a South African investor's capital, if any, should be held in foreign securities under different possible restrictions laid down by the South African Reserve Bank. The main argument advanced in favour of foreign investment is risk reduction through diversification

Importance and implications of antibiotic resistance development in livestock and wildlife farming in South Africa: A Review

Antibiotic resistance (ABR) is regarded as one of today’s major global health challenges. The development of ABR in nature is a complex phenomenon with many influencing factors, of which the farming industry is labelled a significant contributor. The transfer of ABR to humans, which usually occurs via the food chain, is of concern for human health. A food source that is increasing in popularity is game meat, which is farmed widely in South Africa. The natural environment, including wildlife, is not isolated from the rest of the farm, and thus could be a source of ABR or possibly a transfer vector. It is therefore important to assess the ABR situation in wildlife species and the factors that influence its emergence and transfer. Elements that play a part in the development of ABR in game species include certain harvesting and slaughtering and other farming practices and closer contact with humans and other farm animals. Additionally, natural transfer vectors include wind, water, manure, crops and animals. Worryingly, there is lack of knowledge of this situation owing to inadequate monitoring, documentation and control of antibiotics in the farming industry. The objective of this review was to gain better understanding of this situation, which would aid in the development of surveillance systems and methods to prevent or hinder the development of ABR in wildlife species.Keywords: Antimicrobial resistance, food-borne pathogens, game meat, surveillance systems, zoonose

Modeling Group Perceptions Using Stochastic Simulation: Scaling Issues in the Multiplicative AHP

This paper proposes a new decision support approach for applying stochastic simulation to the multiplicative analytic hierarchy process (AHP) in order to deal with issues concerning the scale parameter. The paper suggests a new approach that captures the influence from the scale parameter by making use of probability distributions. Herein, the uncertainty both with regard to the scale and the inherent randomness from the parameter is captured by probabilistic input and output distributions. Provided that each alternative and criteria under consideration are independent it is assumed that the embedded uncertainty from the progression factors remains the same. The result is then an interval estimate for each alternative’s final scores. This can lead to overlapping intervals of scores which may be interpreted as possible rank reversals. Thus, the decision support approach makes it possible to calculate the probability of overlapping for any given set of pairwise comparisons.22 page(s

A phenomenological model of the electrically stimulated auditory nerve fiber: temporal and biphasic response properties

We present a phenomenological model of electrically stimulated auditory nerve fibers (ANFs). The model reproduces the probabilistic and temporal properties of the ANF response to both monophasic and biphasic stimuli, in isolation. The main contribution of the model lies in its ability to reproduce statistics of the ANF response (mean latency, jitter, and firing probability) under both monophasic and cathodic-anodic biphasic stimulation, without changing the model's parameters. The response statistics of the model depend on stimulus level and duration of the stimulating pulse, reproducing trends observed in the ANF. In the case of biphasic stimulation, the model reproduces the effects of pseudomonophasic pulse shapes and also the dependence on the interphase gap (IPG) of the stimulus pulse, an effect that is quantitatively reproduced. The model is fitted to ANF data using a procedure that uniquely determines each model parameter. It is thus possible to rapidly parameterize a large population of neurons to reproduce a given set of response statistic distributions. Our work extends the stochastic leaky integrate and fire (SLIF) neuron, a well-studied phenomenological model of the electrically stimulated neuron. We extend the SLIF neuron so as to produce a realistic latency distribution by delaying the moment of spiking. During this delay, spiking may be abolished by anodic current. By this means, the probability of the model neuron responding to a stimulus is reduced when a trailing phase of opposite polarity is introduced. By introducing a minimum wait period that must elapse before a spike may be emitted, the model is able to reproduce the differences in the threshold level observed in the ANF for monophasic and biphasic stimuli. Thus, the ANF response to a large variety of pulse shapes are reproduced correctly by this model

Bionic inspired study of heat pipe from plant water migration

Heat pipe is well regarded as super thermal conductor and has a wide range of applications in the variety of industry sections. A great number of researches have been done on enhancing the performance of heat pipe through improving the flow pattern. The research on plant water migration based on bionic engineering approach provides a very interesting path to the fluid flow enhancement inside heat pipe, and improvement of inner structure as well. The main forces that drive the water migrates in plants are capillary effect, friction, gravity and transpiration effect, and which are also the main driven forces in heat pipe. Although most researches on heat pipe focus on capillary effect against gravity, transpiration effect is still very important as dragging force occurs when water evaporates. And all these can be investigated through plant water migration. A mathematical model describing the water migration process in plant is proposed in this paper. And the result obtained from mathematical calculation is compared with the experimental measured result using Nuclear Magnetic Resonance (NMR) technology. The perfect matching between the two results confirmed the possibility of using the mathematical model to analyze fluid flow in micro channels, including heat pipe. And it also successfully put transpiration effect and friction into consideration, which give out a clearer view of the forces inside heat pipe for further research

Investigating the Electrical Properties of Different Cochlear Implants.

AIM: This study characterises and compares electrical properties and current spread across four different makes of cochlear implants with differing electrode designs using a 3D-printed artificial cochlear model. BACKGROUND: Cochlear implants are currently limited by current spread within the cochlea, which causes low spectral resolution of auditory nerve stimulation. Different cochlear implant makes vary in electrode size, shape, number, and configuration. How these differences affect cochlear implant current spread and function is not well known. METHOD: Each cochlear implant was inserted into a linear cochlear model containing recording electrodes along its length. Biphasic monopolar stimulation of each implant electrode was carried out, and the resultant waveform and transimpedance matrix (TIM) data obtained from the recording electrodes. This was repeated with each implant rotated 180 degrees in the cochlea model to examine the effects of electrode orientation. Impedance spectroscopy was also carried out at the apex, middle, and base of the model. RESULTS: The four cochlear implants displayed similar TIM profiles and waveforms. One hundred eighty degrees rotation of each cochlear implant made little difference to the TIM profiles. Impedance spectroscopy demonstrated broad similarities in amplitude and phase across the implants, but exhibited differences in certain electrical parameters. CONCLUSION: Implants with different designs demonstrate similar electrical performance, regardless of electrode size and spacing or electrode array dimension. In addition, rotatory maneuvers during cochlear implantation surgery are unlikely to change implant impedance properties.The Wellcome Trust (204845/Z/16/Z), the Evelyn Trust, the Cambridge Hearing Trus

Rescue and Regrowth of Sensory Nerves Following Deafferentation by Neurotrophic Factors

Trauma and loss of cochlear inner hair cells causes a series of events that result first in the retraction of the peripheral processes of the auditory nerve, scar formation in the organ of Corti, and over the course of weeks to months (depending on the species) the loss of auditory nerve cell bodies (spiral ganglion cells). Neurotrophic factors play an important role in the mature nervous system as survival factors for maintenance and protection and also can play a role in regrowth. Studies in the cochlea now show that application of exogenous neurotrophic factors can enhance survival of spiral ganglion cells after deafness and induce regrowth of peripheral processes, perhaps by replacing lost endogenous factors. Combinations of factors may be most effective for achieving greatest survival and regrowth. Our studies find that brain-derived neurotrophic factor (BDNF) and glial-line-derived neurotrophic factor (GDNF) are very effective at enhancing spiral ganglion cell survival following deafness from ototoxic drugs or noise. It has also been found that BDNF plus fibroblast growth factor (FGF) is very effective at inducing process regrowth. Electrical stimulation also acts to enhance spiral ganglion cell survival, and the combination of electrical stimulation and neurotrophic factors could prove a most effective intervention.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73558/1/j.1749-6632.1999.tb08650.x.pd