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

Productivity and Ownership Changes in the Supermarket Industry

Agribusiness, Industrial Organization,

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

From spatial perception to cognitive mapping: how is the flow of information controlled?

Most models of cognitive mapping would suggest that the process begins by constructing some form of a structural representation of the environment visited. From the latter representation, one develops a conceptual view of the environment. The flow of information in the process is almost unidirectional, from perception to conception. In this paper, I argue that this process is inappropriate for a human cognitive mapping process. The latter process should begin with some symbolic notions of places and never needed to construct explicitly a structural representation of the environment visited. Humans' ability to visualise the structural details in a familiar environment comes from the increasingly detailed grounding of its symbols to the real world as a result of familiarisation and attention to details

5 Stages Improvement Model (5sim) For Integrating Lean Manufacturing And Six Sigma Dmaic

Pada permulaan abad ke dua puluh satu, ekonomi dunia telah menjadi semakin terbuka kepada persaingan berbanding dengan abad-abad yang lalu. At the dawning of the twenty first century, the world economy had become more open to competition as it had been for the past centuries

Concatenated Space Time Block Codes and TCM, Turbo TCM Convolutional as well as Turbo Codes

Space-time block codes provide substantial diversity advantages for multiple transmit antenna systems at a low decoding complexity. In this paper, we concatenate space-time codes with Convolutional Codes (CC), Turbo Convolutional codes (TC), Turbo BCH codes (TBCH), Trellis Coded Modulation (TCM) and Turbo Trellis Coded Modulation (TTCM) schemes for achieving a high coding gain. The associated performance and complexity of the coding schemes is compared