Sales restriction, quality selection and the mode of competition

A regulator imposing “sales restrictions” on firms competing in oligopolistic markets may enhance quality provision by the firms. Moreover, for most restrictions levels, the impact on quality selection is invariant to the mode of competition

Local Competition, Inbreeding, and the Evolution of Sex-Biased Dispersal.

Using game theory, we developed a kin-selection model to investigate the consequences of local competition and inbreeding depression on the evolution of natal dispersal. Mating systems have the potential to favor strong sex biases in dispersal because sex differences in potential reproductive success affect the balance between local resource competition and local mate competition. No bias is expected when local competition equally affects males and females, as happens in monogamous systems and also in polygynous or promiscuous ones as long as female fitness is limited by extrinsic factors (breeding resources). In contrast, a male-biased dispersal is predicted when local mate competition exceeds local resource competition, as happens under polygyny/promiscuity when female fitness is limited by intrinsic factors (maximal rate of processing resources rather than resources themselves). This bias is reinforced by among-sex interactions: female philopatry enhances breeding opportunities for related males, while male dispersal decreases the chances that related females will inbreed. These results meet empirical patterns in mammals: polygynous/promiscuous species usually display a male-biased dispersal, while both sexes disperse in monogamous species. A parallel is drawn with sex-ratio theory, which also predicts biases toward the sex that suffers less from local competition. Optimal sex ratios and optimal sex-specific dispersal show mutual dependence, which argues for the development of coevolution models.

Cannes 21-1-20, Miss Ryan [Elisabeth] et Ritchie [Josiah] [contre] Mlle Lenglen [Suzanne] et Albarran [Pierre] [tournoi de lawn-tennis du Carlton-Club de Cannes] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57735

Cannes, 21-1-20, prince Philippe de Bourbon [jouant au tennis] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57740

Cannes 21-1-20, lord Rochsavage [i. e. marquis de Cholmondeley au tournoi de lawn-tennis du Carlton-Club de Cannes] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57737

B. [Blanche] Amblard, S. [Suzanne] Amblard [joueuses de tennis du Sporting club de Paris, rue de Saussure] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57566

Cannes 21-1-20, Miss Lenglen [Suzanne] et Albarran [Pierre] [tournoi de lawn-tennis du Carlton-Club de Cannes] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57731

Cannes 21-1-20, Eddis [tournoi de lawn-tennis du Carlton-Club de Cannes] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57736

Ritchie [Josia George] [et] Hunter [Alfred C.] Cannes, 21-1-20 [tournoi de lawn-tennis du Carlton de Cannes] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57738

Gobert, 3-11-19 [champion du monde de tennis sur court couvert] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57028

Cannes, 21-1-20, prince Philippe de Bourbon [jouant au tennis] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57739

16/11/19, championnats du monde de tennis, rue [de] Saussure [Paris, 17e arrondissement] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 56947

Telecommunications Competition Survey for Retail Local Voice Services in Iowa, January 26, 2004

Survey of retail local voice services for Iowa Utilities Board

Miss Lenglen, Cannes 21-1-20 [au tournoi de lawn-tennis du Carlton-Club de Cannes] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 57734