Do we (still) need to regulate fixed network retail markets?

In the beginning of fixed network liberalisation in Europe in the late 1990s, the main concern of regulators was to lower calls prices. This was done by introducing wholesale regulation and promoting service based competition. Some years later, the concern of some regulators turned from too high calls prices to too low calls prices which might ‘squeeze’ entrants out of the market. We look at a simple model in which this development is explained by increasing competitive pressure from an ‘outside opportunity’, e.g. mobile telephony. We conclude that a margin squeeze is not necessarily used by the incumbent as a device to drive competitors out of the market and increase market power but can also result from increased inter-model competition. If this is the case, we argue that regulators should consider alternatives to cost oriented access prices such as retail minus or complete deregulation.access regulation, vertical integration, foreclosure, price squeeze, telecommunications, fixed networks

Margin Squeeze in Fixed-Network Telephony Markets – competitive or anticompetitive?

This paper looks at the effects of different forms of wholesale and retail regulation on retail competition in fixed network telephony markets. We explicitly model two asymmetries between the incumbent operator and the entrant: (i) While the incumbent has zero marginal costs, the entrant has the wholesale access charge as (positive) marginal costs; (ii) While the incumbent is setting a two-part tariff at the retail level (fixed fee and calls price), the entrant can only set a linear price for calls. Competition from other infrastructures such as mobile telephony or cable is modelled as an ‘outside opportunity’ for consumers. We find that a horizontally differentiated entrant with market power may be subject to a margin squeeze due to double marginalization but will never be completely foreclosed. Entrants without market power might be subject to a margin squeeze if the wholesale access price is set at average costs and competitive pressure from other infrastructures increases. We argue that a wholesale price regulation at average costs is not optimal in such a situation and discuss retail minus and deregulation as potential alternatives.access regulation, foreclosure, margin squeeze, telecommunications, fixed networks

Margin squeeze in fixed-network telephony markets: competitive or anticompetitive?

This paper looks at the effects of different forms of wholesale and retail regulation on retail competition in fixed network telephony markets. We explicitly model two asymmetries between the incumbent operator and the entrant: (i) While the incumbent has zero marginal costs, the entrant has the wholesale access charge as (positive) marginal costs; (ii) While the incumbent is setting a two-part tariff at the retail level (fixed fee and calls price), the entrant can only set a linear price for calls. Competition from other infrastructures such as mobile telephony or cable is modelled as an outside opportunity for consumers. We find that a horizontally differentiated entrant with market power may be subject to a margin squeeze due to double marginalization but will never be completely foreclosed. Entrants without market power might be subject to a margin squeeze if the wholesale access price is set at average costs and competitive pressure from other infrastructures increases. We argue that a wholesale price regulation at average costs is not optimal in such a situation and discuss retail minus and deregulation as potential alternatives

Do we (still) need to regulate fixed network retail markets?

In the beginning of fixed network liberalisation in Europe in the late 1990s, the main concern of regulators was to lower calls prices. This was done by introducing wholesale regulation and promoting service based competition. Some years later, the concern of some regulators turned from too high calls prices to too low calls prices which might squeeze entrants out of the market. We look at a simple model in which this development is explained by increasing competitive pressure from an outside opportunity, e.g. mobile telephony. We conclude that a margin squeeze is not necessarily used by the incumbent as a device to drive competitors out of the market and increase market power but can also result from increased inter-model competition. If this is the case, we argue that regulators should consider alternatives to cost oriented access prices such as retail minus or complete deregulation

Zu Eugen Finks Bestimmung der europäischen Krise der Bildung

Dieser Text hat dreifachen Sinn: erstens, ich war damals (in Frieburg) Assistent beim Prof. Eugen Fink; zweitens, Prof. Milan Kangrga war sehr nahe und schon befreundet mit E. Fink und hat bei ihm in Freiburg einige Vortrage gehalten; drittens, Fink war Mitglied des Redaktionsrats der Zeitschrift Praxis und auch Teilnehmer der Korčula Sommerschule. Außerdem, Fink war der erste ausländische Philosoph, der nach dem zweiten Weltkrieg einen Vortrag in der Abteilung für Philosophie der Philosophischen Fakultät in Zagreb (1954) gehalten hat, auf das Thema »über den Begriff der Arbeit«. Deshalb halte ich für angemessen, in dieser Festschrift für seinen guten Freund Milan Kangrga zu seinem 80. Geburtstag einen solchen Beitrag zu widmen

SFT-inspired Algebraic Structures in Gauge Theories

We consider gauge theories in a String Field Theory-inspired formalism. The constructed algebraic operations lead in particular to homotopy algebras of the related BV theories. We discuss invariant description of the gauge fixing procedure and special algebraic features of gauge theories coupled to matter fields.Comment: LaTeX2e, 26 pages; minor revisions after referee's remarks, typos corrected, title changed, references added, J. Mathematical Physics, in pres

The Human Dive Reflex During Consecutive Apnoeas in Dry and Immersive Environments: Magnitude and Synchronicity

Introduction: The human dive reflex (HDR), an O2 conserving reflex, is characterised by an interplay of central parasympathetic and peripheral sympathetic reactions, which are presumed to operate independently of each other. The HDR is fully activated during apnoea with facial immersion in water and complete immersion in water is thought to increase the magnitude of HDR during consecutive apnoeas. A comparison of HDR activity between consecutive apnoeas in full-body immersion with consecutive apnoeas in dry conditions has not been fully explored. Also, the interplay between parasympathetic and sympathetic reactions involved in the HDR has not been thoroughly analysed. Methods: 11 human volunteers performed 3 consecutive 60 s apnoeas with facial immersion in dry conditions (FIDC) and 3 consecutive apnoeas with facial immersion in full immersion (FIFI). Heart rate (HR), R-R interval (RRI), finger pulse amplitude (FPA), splenic width (SW) and SpO2 were all measured before, during and after apnoeas. A one-way ANOVA using Dunn’s post hoc test was performed to assess HDR activity, and a Pearson’s correlation test was performed to assess HDR synchronisation between physiological parameters during both conditions. Results: Although HDR activity was not significantly different between both conditions, HR and RRI showed progressively greater changes during FIFI compared with FIDC, while SW and FPA changes were relatively equivalent. During FIDC, significant correlations were found between SW & SpO2 and FPA & SpO2. During FIFI, significant correlations were found between RRI & FPA, SW & FPA, HR & SpO2 and FPA & SpO2. Discussion: While there was no significant difference found between HDR activity during FIDC and FIFI, consecutive apnoeas during FIFI triggered a greater magnitude of cardiac activity. Furthermore, significant correlations between RRI and SW with FPA indicate a crosstalk between parasympathetic tone with splenic contraction and increased peripheral sympathetic outflow during FIFI compared to FIDC. In conclusion, HDR activity during consecutive apnoeas does not differ between FIDC and FIFI. There appears to be however a greater level of synchronicity during apnoeas in FIFI compared to FIDC and that this is most likely due to the physiological effects of immersion, which could induce neural recruitment and increased cross talk of HDR pathways

Reducing errors in guided implant surgery to optimize treatment outcomes.

Clinical considerations and treatment criteria in implant placement are constantly evolving. Prosthetically driven implant surgery has become the standard of care to improve short and long-term functional and esthetic outcomes. Therefore, implant position and angulation are planned according to the available bone, anatomical structures, and the requirements of the future prosthetic superstructure. In parallel with these developments, significant progress has been made in data imaging and different software technologies to allow the integration of data within a digital file format. Digitalization in implant surgery enables optimal planning of implant position, as well as the ability to transfer this planning to the surgical field-a process defined as "computer-supported implant planning and guided surgery." The aims of the present review are as follows: (a) to critically appraise the indications and potential "added value" of guided implant surgery, elaborating the main differences between dynamic and static guidance; and (b) to discuss the most important clinical considerations relevant for the different steps of the workflow that might influence the surgical outcome and to offer recommendations on how to avoid or reduce process errors in order to optimize treatment outcomes