On bidding markets: the role of competition

This paper analyzes the effects of industrial concentration on bidding behaviour and hence, on the seller´s expected proceeds. These effects are studied under the CIPI model, an affiliated value set-up that nests a variety of valuation and information environments. We formally decompose the revenue effects coming from less competition into four types: a competition effect, an inference effect, a winner´s curse effect and a sampling effect. The properties of these effects are discussed and conditions for (non) monotonicity of both the equilibrium bid and revenue are stated. Our results suggest that it is more likely that the seller benefits from less competition in markets with more complete valuation and information structures

Optimal takeover contests with toeholds

This paper characterizes how a target firm should be sold when the possible buyers (bidders) have prior stakes in its ownership (toeholds). We find that the optimal mechanism needs to be implemented by a non-standard auction which imposes a bias against bidders with high toeholds. This discriminatory procedure is such that the target´s average sale price is increasing in both the size of the common toehold and the degree of asymmetry in these stakes. It is also shown that a simple mechanism of sequential negotiation replicates the main properties of the optimal procedure and yields a higher average selling price than the standard auctions commonly used in takeover battles

Supersymmetric effects in rare semileptonic decays of B and K mesons

Rare flavour-changing neutral-current transitions of the type $s \to d \ell^+\ell^-(\nu\bar\nu)$ and $b \to s \ell^+\ell^-(\nu\bar\nu)$ are analysed in supersymmetric extensions of the Standard Model with generic flavour couplings. It is shown that these processes are particularly sensitive to the left--right mixing of the squarks and that, in the presence of non-universal $A$ terms, they could lead to unambiguous signatures of new physics in exclusive $K$ and $B$ meson decays.Comment: 15 pages, Latex, invited talk at RADCOR 2000 (Carmel CA, USA, Sept. 2000

Theory of radiative and rare B decays

We present a concise theoretical overview of radiative and rare B decays mediated by flavour-changing neutral-current transitions of the type b->s(d)gamma and b->s(d)l+l-.Comment: 7 pages, 4 figures. Talk given at 9th International Conference on B Physics at Hadron Machines (Beauty 2003), Pittsburgh, Pennsylvania, 14-18 Oct 200

Effective theories of electroweak symmetry breaking

We present a brief review of recent attempts to construct effective theories to describe the breaking of the electroweak symmetry in extensions of the Standard Model with new strongly interacting dynamics around the TeV scale. Particular attention is devoted to the analogies of Higgsless models with Chiral Perturbation Theory (the low-energy limit of QCD).Comment: 12 pages, invited talk at the 6th International Workshop on Chiral Dynamics, CD09, July 6-10, 2009, Bern, Switzerland (v2: minor typos corrected)

Rare decays: theory vs. experiments

We present an overview of rare K, D and B decays. Particular attention is devoted to those flavour-changing neutral-current processes of K and B mesons that offer the possibility of new significant tests of the Standard Model. The sensitivity of these modes to physics beyond the Standard Model and the status of their experimental study are also discussed.Comment: 20 pages, 9 figures, invited talk at 20th International Symposium on Lepton and Photon Interactions at High Energies, Rome, August 2001; v2 & v3: minor modifications, few references adde