Price markups in oligopoly models with differentiated products

I show that the relationship between the toughness of price competition and market size in oligopoly models depends on assumptions about the shape of preferences. In a Perloff and Salop model of nonlocalized taste for variety, price-cost margins remain bounded above zero as market size grows infinitely large, even as the number of firms grows without bound. By contrast, a Salop circle model of localized preferences generates price-cost margins that fall to zero as market size grows large. The toughness of price competition never reaches competitive levels if nonlocalized preferences generate entry opportunities that expand the set of product variants. The toughness of price competition rises to competitive levels if localized preferences generate entry opportunities to "fill in" product space. I also outline an empirical test for boundedness of price-cost margins by examining boundedness of firm revenues in chain and non-chain restaurants in Census of Retail Trade data.

Full-Rate, Full-Diversity Adaptive Space Time Block Coding for Transmission over Rayleigh Fading Channels

A full-rate, full-diversity Adaptive Space Time Block Coding (ASTBC) scheme based on Singular Value Decomposition (SVD) is proposed for transmission over Rayleigh fading channels. The ASTBC-SVD scheme advocated is capable of providing both full-rate and full-diversity for any number of transmit antennas, Nt, provided that the number of receive antennas, Nr, equals to Nt. Furthermore, the ASTBC-SVD scheme may achieve an additional coding gain due to its higher product distance with the aid of the block code employed. In conjunction with SVD, the “water-filling” approach can be employed for adaptively distributing the transmitted power to the various antennas transmit according to the channel conditions, in order to further enhance the attainable performance. Since a codeword constituted by Nt symbols is transmitted in a single time slot by mapping the Nt symbols to the Nt transmit antennas in the spatial domain, the attainable performance of the ASTBC-SVD scheme does not degrade, when the channel impulse response values vary from one time slot to the next. Hence, the proposed ASTBC-SVD scheme is attractive in the context of both uncorrelated and correlated Rayleigh fading channels. The performance of the proposed scheme was evaluated, when communicating over uncorrelated Rayleigh fading channels. Explicitly, an Eb/N0 gain of 2.5 dB was achieved by the proposed ASTBC-SVD scheme against Alamouti’s scheme [1], when employing Nt = Nr = 2 in conjunction with 8PSK

Statutory audit and corporate governance: Evidence from the small and medium-sized AIM companies

This thesis revolves around the “triangle relationship” among the shareholders, directors, and statutory auditors of a sample of small and medium-sized AIM companies of the London Stock Exchange for the financial periods covering 2010 to 2015 towards the demand and supply of statutory audit services, aiming to provide answers to the research questions of three empirical studies as follows. Firstly, what are the drivers of statutory audit fee? Secondly, what are the triggers of statutory auditor switching? Thirdly, what are the determinants of audit report lag? The first empirical study of this thesis shows that the small and medium-sized AIM companies that formed audit committee tends to pay lower statutory audit fee while a newly appointed statutory auditor tends to charge lower statutory audit fee at the initial engagement. However, the dual role of nominated adviser cum broker or the newly appointed chief executive officer does not influence the level of statutory audit fee. The second empirical study of this thesis reveals that the appointment of new chief executive officer or new nominated adviser can trigger the statutory auditor switching in the following year. In addition, the small and medium-sized AIM companies are more likely to switch statutory auditors when the level of statutory audit fee or non-audit fee is costlier. On the other hand, they are also more likely to switch statutory auditors if they have audit committee and received modified audit report. The third empirical study of this thesis demonstrates that the extent of audit report lag for the small and medium-sized AIM companies is explained by the level of auditor-client negotiations and not by the corporate governance characteristics. The audit report lag is longer when the level of discretionary accruals is higher or when modified audit report is issued. However, the existence of audit committee, chief executive officer cum chairman, or nominated adviser cum broker does not enhance the financial reporting timeliness. Other than contributing to the existing literature into the aspects of statutory audit for smaller listed companies, this thesis also provides the preliminary and entirely new evidence on the influential role of the unique advisory feature of nominated adviser when fixing the statutory audit fee, deciding the statutory auditor switching, and determining the audit report lag of AIM companies.

Productivity and Ownership Changes in the Supermarket Industry

Agribusiness, Industrial Organization,

A Turbo Detection and Sphere-Packing-Modulation-Aided Space-Time Coding Scheme

Arecently proposed space-time block-coding (STBC) signal-construction method that combines orthogonal design with sphere packing (SP), referred to here as STBC-SP, has shown useful performance improvements over Alamouti’s conventional orthogonal design. In this contribution, we demonstrate that the performance of STBC-SP systems can be further improved by concatenating SP-aided modulation with channel coding and performing demapping as well as channel decoding iteratively. We also investigate the convergence behavior of this concatenated scheme with the aid of extrinsic-information-transfer charts. The proposed turbo-detected STBC-SP scheme exhibits a “turbo-cliff” at Eb/N0 = 2.5 dB and provides Eb/N0 gains of approximately 20.2 and 2.0 dB at a bit error rate of 10?5 over an equivalent throughput uncoded STBC-SP scheme and a turbo-detected quadrature phase shift keying (QPSK) modulated STBC scheme, respectively, when communicating over a correlated Rayleigh fading channel. Index Terms—EXIT charts, iterative demapping, multidimensional mapping, space-time coding, sphere packing, turbo detection

Does Misclassification of Equity Funds Exist? Evidence from Malaysia

Applying the style analysis developed by Sharpe (1988, 1992), this paper investigates the classification of equity funds in Malaysia. A methodology for creating purified mutual fund style indexes is used to verify existing classifications. The paper concludes that an improper classification of funds would not only cause mismatch between investors objectives and funds’ profile, it also affects the process of income smoothing in the lifecycle of investors. Besides estimating the possible economic impact due to misclassification, this study highlights the importance of a proper classification system of equity funds in Malaysian context and its implication towards investor’s protection.Mutual Fund Classification; Style Analysis; Investor’s Protection

How Albot0 finds its way home: a novel approach to cognitive mapping using robots

Much of what we know about cognitive mapping comes from observing how biological agents behave in their physical environments, and several of these ideas were implemented on robots, imitating such a process. In this paper a novel approach to cognitive mapping is presented whereby robots are treated as a species of their own and their cognitive mapping is being investigated. Such robots are referred to as Albots. The design of the first Albot, Albot0, is presented. Albot0 computes an imprecise map and employs a novel method to find its way home. Both the map and the returnhome algorithm exhibited characteristics commonly found in biological agents. What we have learned from Albot0’s cognitive mapping are discussed. One major lesson is that the spatiality in a cognitive map affords us rich and useful information and this argues against recent suggestions that the notion of a cognitive map is not a useful one

Development and optimisation of tracking methods to facilitate movement ecology research for the conservation management of black cockatoos in Western Australia

The three black cockatoo species endemic to south-west Western Australia – Carnaby’s cockatoo (Calyptorhynchus latirostris), Baudin’s cockatoo (C. baudinii) and forest red-tailed black cockatoo (C. banksii naso) are threatened and have Recovery Plans guiding conservation efforts. Threats include habitat loss due to land clearing for urban, agricultural and industrial development; competition with other species for nest hollows; poaching; disease; vehicle-strike and illegal shooting. This research built on previous black cockatoo research with an overall aim to develop and validate reliable methods to track all three species, to gain insight into their movement, distribution, habitat use, activity and behaviour. In an initial proof of concept trial, we attached tail-mounted tags to two Baudin’s cockatoos. Both birds were successfully tracked for several months after release, demonstrating satellite telemetry can be used to locate and track forest species. We then developed a double-tag mounting protocol to attach a tail-mounted ARGOS PTT satellite tag and back-mounted solar-powered UvA-BiTS GPS tag to captive black cockatoos. The combination of UvA-BiTS back mount and ventral tail mounted Telonics tags was the best tolerated and provided excellent GPS and ARGOS satellite location data with no interference between the two types of tag. The focus then moved to the development of an automated classifier tool that used accelerometer data from UvA-BiTS GPS tags to remotely identify behaviours and calculate activity budgets. Using accelerometer data from 15 birds post-release, we determined black cockatoos spend most of their time at rest, interspersed with foraging activity through the day and some movement between roost sites and feeding habitat. To maximise the retention time of tail-mounted tags, the tail feather life span and time of moulting was studied using moulted tail feathers from captive cockatoos and tagged bird post-release. Captive cockatoos had a mean feather lifespan of 410 days, suggesting tail feathers do not always moult annually. Peak tail feather moulting occurs from December to March, the non-breeding period. The optimal time to attach tail mounted tags is from May to September. The development and optimisation of tracking methodologies for use on black cockatoos has facilitated the tracking of all three species in the wild. This research has provided data which have enabled identification of key roosting, foraging and breeding habitat and determination of flock movement patterns and habitat use at a landscape scale across the species’ distribution ranges. This information is being used to guide black cockatoo conservation management in relation to habitat protection and restoration