Variations on a Montagovian theme

What are the objects of knowledge, belief, probability, apriority or analyticity? For at least some of these properties, it seems plausible that the objects are sentences, or sentence-like entities. However, results from mathematical logic indicate that sentential properties are subject to severe formal limitations. After surveying these results, I argue that they are more problematic than often assumed, that they can be avoided by taking the objects of the relevant property to be coarse-grained (“sets of worlds”) propositions, and that all this has little to do with the choice between operators and predicates

Changing minds in a changing world

I defend a general rule for updating beliefs that takes into account both the impact of new evidence and changes in the subject’s location. The rule combines standard conditioning with a “shifting” operation that moves the center of each doxastic possibility forward to the next point where information arrives. I show that well-known arguments for conditioning lead to this combination when centered information is taken into account. I also discuss how my proposal relates to other recent proposals, what results it delivers for puzzles like the Sleeping Beauty problem, and whether there are diachronic constraints on rational belief at all

Against magnetism

Magnetism in meta-semantics is the view that the meaning of our words is determined in part by their use and in part by the objective naturalness of candidate meanings. This hypothesis is commonly attributed to David Lewis, and has been put to philosophical work by Brian Weatherson, Ted Sider and others. I argue that there is no evidence that Lewis ever endorsed the view, and that his actual account of language reveals good reasons against it

Contingent identity

It is widely held that if an object a is identical (or non-identical) to an object b, then it is necessary that a is identical (non-identical) to b. This view is supported an argument from Leibniz's Law and a popular conception of de re modality. On the other hand, there are good reasons to allow for contingent identity. Various alternative accounts of de re modality have been developed to achieve this kind of generality, and to explain what is wrong with the argument from Leibniz's Law

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