Bundling and competition for slots: Sequential pricing

In this paper we study, as in Jeon-Menicucci (2009), competition between sellerswhen each of them sells a portfolio of distinct products to a buyer having limitedslots. This paper considers sequential pricing and complements our main paper (Jeon-Menicucci, 2009) that considers simultaneous pricing.First, Jeon-Menicucci (2009) find that under simultaneous individual pricing, equilibriumoften does not exist and hence the outcome is often inefficient. By contrast,equilibrium always exists under sequential individual pricing and we characterize it inthis paper. We find that each seller faces a trade-off between the number of slots heoccupies and surplus extraction per product, and there is no particular reason thatthis leads to an efficient allocation of slots.Second, Jeon-Menicucci (2009) find that when bundling is allowed, there alwaysexists an efficient equilibrium but inefficient equilibria can also exist due to purebundling (for physical products) or slotting contracts. Under sequential pricing,we find that all equilibria are efficient regardless of whether firms can use slottingcontracts, and both for digital goods and for physical goods. Therefore, sequentialpricing presents an even stronger case for laissez-faire in the matter of bundling thansimultaneous pricing.

Bundling and competition for slots: On the portfolio effects of bundling

We consider competition among sellers when each of them sells a portfolio ofdistinct products to a buyer having limited slots. We study how bundling affectscompetition for slots. Under independent pricing, equilibrium often does not existand hence the outcome is often inefficient. When bundling is allowed, each sellerhas an incentive to bundle his products and an efficient equilibrium always exists.Furthermore, in the case of digital goods, all equilibria are efficient if slotting contracts are prohibited. We also identify portfolio effects of bundling and analyze theconsequences on horizontal mergers. Finally, we derive clear-cut policy implications.

Is bundling anticompetitive?

I analyze the implications of bundling on price competition in a market for complementary products. Using a model of imperfect competition with product differentiation, I identify the incentives to bundle for two types of demand functions and study how they change with the size of the bundle. With an inelastic demand, bundling creates an advantage over uncoordinated rivals who cannot improve by bundling. I show that this no longer holds with an elastic demand. The incentives to bundle are stronger and the market outcome is symmetric bundling, the most competitive one. Profits are lowest and consumer surplus is maximized.

Pure braid subgroups of braided Thompson's groups

"Vegeu el resum a l'inici del document del fitxer adjunt."

Pure motives, mixed motives and extensions of motives associated to singular surfaces

We first recall the construction of the Chow motive modelling intersection cohomology of a proper surface X and study its fundamental properties. Using Voevodsky's category of effective geometrical motives, we then study the motive of the exceptional divisor D in a non-singular blow-up of X. If all geometric irreducible components of D are of genus zero, then Voevodsky's formalism allows us to construct certain one-extensions of Chow motives, as canonical subquotients of the motive with compact support of the smooth part of X. Specializing to Hilbert-Blumenthal surfaces, we recover a motivic interpretation of a recent construction of A. Caspar.

Endogenous Mergers of Complements with Mixed Bundling

This paper studies endogenous mergers of complements with mixed bundling, by allowing both for joint and separate consumption. After merger, partner fi…rms decrease the price of the bundled system. Besides, when markets for individual components are suffi…ciently important, partner …firms raise prices of stand-alone products, exploiting their monopoly power in local markets and making substitute 'mix-and-match' composite products less attractive to consumers. Even though these effects favor the pro…fitability of mergers, merging is not always an equilibrium outcome. The reason is that outsiders respond by cutting their prices to retain their market share, and mergers can be unprofitable when competition is intense. From a welfare analysis, we observe that the number of mergers observed in equilibrium may be either excessive (when markets for individual components are important) or suboptimal (when markets for individual components are less important). Keywords: complements; merger; mixed bundling; separate consumption JEL classi…fication: L13; L41; D43

Bundling electronic journals and competition among publishers

Site licensing of e-journals has been revolutionizing the way academicinformation is distributed. However, many librarians are concerned aboutthe possibility that publishers might abuse site licensing by practicingbundling. In this paper, we analyze the private and social incentives forthe publishers to use bundling in the context of STM electronic journalmarket. In the short run in which the number of journals is exogenouslygiven, we find a strong conflict between the two incentives: each publisherfinds bundling optimal and bundling increases the industry profit butreduces social welfare. However, in the long run we find that publishersmight have higher incentives to introduce new journals under bundlingthan without bundling and, in this case, bundling can reduce the industryprofit while increasing social welfare. Finally, we examine publishers incentive to provide links to the websites of the rival publishers underbundling and show that even asymmetric publishers have incentive tointerconnect.

Optimal estimation of two-qubit pure-state entanglement

We present optimal measuring strategies for an estimation of the entanglement of unknown two-qubit pure states and of the degree of mixing of unknown single-qubit mixed states, of which N identical copies are available. The most general measuring strategies are considered in both situations, to conclude in the first case that a local, although collective, measurement suffices to estimate entanglement, a nonlocal property, optimally.

Quantization of AdS3 black holes in external fields: semiclassical results from pure gravity

(2+1)-dimensional anti-de Sitter (AdS) gravity is quantized in the presence of an external scalar field. We find that the coupling between the scalar field and gravity is equivalently described by a perturbed conformal field theory at the boundary of AdS3. This allows us to perform a microscopic computation of the transition rates between black hole states due to absorption and induced emission of the scalar field. Detailed thermodynamic balance then yields Hawking radiation as spontaneous emission, and we find agreement with the semiclassical result, including greybody factors. This result also has application to four and five-dimensional black holes in supergravity.

Pure sensory neuropathy in patients with primary Sjogren's syndrome: clinical, immunological and electromyographic findings

A pure sensory neuropathy caused by lymphocytic infiltration of the dorsal root ganglia has been reported in a few patients with Sjögren's syndrome. The clinical, immunological, and electromyographic findings of five patients with this type of neuropathy and primary Sjögren's syndrome were reviewed. Typical clinical indications were the presence of a chronic asymmetrical sensory deficit, initial disease in the hands with a predominant loss of the vibratory and joint position senses, and an association with Adie's pupil syndrome or trigeminal sensory neuropathy. The simultaneous impairment of the central and peripheral evoked cortical potentials suggested that there was a lesion of the neuronal cell body. The neuropathy preceded the diagnosis of Sjögren's syndrome in four patients. Four patients were positive for Ro antibodies, but systemic vasculitis or malignancy was not found after a mean follow up of six years. These findings indicate that in patients with a sensory neuropathy the diagnosis of Sjögren's syndrome has to be considered, even if the patient denies the presence of sicca symptoms, and that appropriate tests must be carried out.

Relaxation and derelaxation of pure and hydrogenated amorphous silicon during thermal annealing experiments

The structural relaxation of pure amorphous silicon a-Si and hydrogenated amorphous silicon a-Si:H materials, that occurs during thermal annealing experiments, has been analyzed by Raman spectroscopy and differential scanning calorimetry. Unlike a-Si, the heat evolved from a-Si:H cannot be explained by relaxation of the Si-Si network strain but it reveals a derelaxation of the bond angle strain. Since the state of relaxation after annealing is very similar for pure and hydrogenated materials, our results give strong experimental support to the predicted configurational gap between a-Si and crystalline silicon.

EMU sovereign debt market crisis: Fundamentals-based or pure contagion?

We empirically investigate whether the transmission of the recent crisis in euro area sovereign debt markets was due to fundamentals-based or pure contagion. To do so, we examine the behaviour of EMU sovereign bond yield spreads with respect to the German bund for a sample of both central and peripheral countries from January 1999 to December 2012. First we apply a dynamic approach to analyse the evolution of the degree of Grangercausality within the 90 pairs of sovereign bond yield spreads in our sample, in order to detect episodes of significantly increased causality between them (which we associate with contagion) and episodes of significantly reduced interconnection (which we associate with immunisation). We then use an ordered logit model to assess the determinants of the occurrence of the episodes detected. Our results suggest the importance of variables proxying market sentiment and of variables proxying macrofundamentals in determining contagion and immunisation outcomes. Therefore, our findings underline the coexistence of “pure” and “fundamentals-based contagion” during the recent European debt crisis.

EMU sovereign debt market crisis: Fundamentals-based or pure contagion?

We empirically investigate whether the transmission of the recent crisis in euro area sovereign debt markets was due to fundamentals-based or pure contagion. To do so, we examine the behaviour of EMU sovereign bond yield spreads with respect to the German bund for a sample of both central and peripheral countries from January 1999 to December 2012. First we apply a dynamic approach to analyse the evolution of the degree of Grangercausality within the 90 pairs of sovereign bond yield spreads in our sample, in order to detect episodes of significantly increased causality between them (which we associate with contagion) and episodes of significantly reduced interconnection (which we associate with immunisation). We then use an ordered logit model to assess the determinants of the occurrence of the episodes detected. Our results suggest the importance of variables proxying market sentiment and of variables proxying macrofundamentals in determining contagion and immunisation outcomes. Therefore, our findings underline the coexistence of “pure” and “fundamentals-based contagion” during the recent European debt crisis.

Beyond pure public and pure private management models: Partial privatization in the European airport industry

The use of private funding and management is enjoying an increasing trend in airports. The literature has not paid enough attention to the mixed management models in this industry, although many European airports take the form of mixed public-private companies, where ownership is shared between public and private sectors. We examine the determinants of the degree of private participation in the European airport sector. Drawing on a sample of the 100 largest European airports, we estimate a multivariate equation in order to determine the role of airport characteristics, fiscal variables, and political factors on the extent of private involvement. Our results confirm the alignment between public and private interests in partially privatized airports. Fiscal constraints and market attractiveness promote private participation. Integrated governance models and the share of network carriers prevent the presence of private ownership, while the degree of private participation appears to be pragmatic rather than ideological.

Beyond pure public and pure private management models: Mixed firms in the European Airport Industry

The use of private funding and management enjoys an increasing trend in airports. The literature has not paid enough attention to the mixed management models in this industry, although many European airports take the form of mixed firms or Institutional PPP, where ownership is shared between public and private sectors. We examine the determinants of the degree of private participation in the European airport sector. Drawing on a sample of the 100 largest European airports we estimate a multivariate equation in order to determine the role of airport characteristics, fiscal variables and political factors on the extent of private involvement. Our results confirm the alignment between public and private interests in PPPs. Fiscal constraints and market attractiveness promote private participation. Integrated governance models and the share of network carriers prevent the presence of private ownership, while the degree of private participation appears to be pragmatic rather than ideological.