There is a lot of anecdotal evidence that entry of new firms reduces not only prices but also costs. However, it is far from clear how this cost-reduction works. In this paper I investigate three models of how entry may cause cost reduction: managerial incentives, survival of the fittest, and imitation. The models have somewhat different implications for social welfare.

Of all the common afflictions from which humankind suffers, forgetting is probably the most common. Each of us, every day, forgets something we wish we could remember. It might be something we have done, something we intended to do, a fact, a name of a person or restaurant, and so on ad infinitum. As we age, our incidents of forgetting increase and we worry more about them. A whole industry of ...

The ideal intervention paper exercise, from the perspective of the pastoral formation of the student, can be an experience that helps to complete the student’s formation of her or his pastoral identity in a CPE Unit. The development of the paper brings into play the student’s ability to make effective use of her or his religious and spiritual heritage, theological understanding, knowledge of be...

This chapter gives some preliminary material on number theory and algebraic geometry. Section 1 gives basic preliminary notation, both mathematical and logistical. Section 2 describes what algebraic geometry is assumed of the reader, and gives a few conventions that will be assumed here. Section 3 gives a few more details on the field of definition of a variety. Section 4 does the same as Secti...

Background and Purpose We compared the results of conventional angiography, carotid Doppler, and magnetic resonance angiography volume flow rates to determine the clinical utility of volume flow rate assessment of blood flow to the anterior circulation in patients with carotid occlusive disease. Methods From 11 symptomatic patients, a total of 22 extracranial carotid arteries were studied with ...

The main theorem of this paper is that, for every real number < 1 (e.g., = 0:99), only a measure 0 subset of the languages decidable in exponential time are Pn tt-reducible to languages that are not exponentially dense. Thus every Pn tt-hard language for E is exponentially dense. This strengthens Watanabe's 1987 result, that every PO(logn) tt-hard language for E is exponentially dense. The comb...

S_nmry Although many risk factors have been proposed for the aetiology of testicular cancer, onlv a history of cryptorchidism is well established. All risk factors previously suggested have been explored in this study. This population-based case-control study was carried out in nine health regions in England and Wales and included 794 men, aged 15-49 years, diagnosed with a testicular germ cell...

the main objective of the present study was to formulate gastroretentive effervescent sustained release drug delivery systems of risperidone floating tablets with the help of methocel® k15, ethocel® standard 7fp premium, eudragit ® rs100 sustained release polymers to improve its safety profile, bioavailability and patient compliance. risperidone floating tablets were formulated by wet granulati...