This paper describes a novel concept of customer discrimination in the housing market, neighbor discrimination. We develop a matching model with ethnic externalities in which landlords differ in the number of apartments they own within the same building. Larger landlords are more likely to discriminate only if some tenants are prejudiced against the minority group. Observing that minority tenants are less likely than majority group tenants to live in a building with a single large landlord is thus evidence of neighbor discrimination. We show empirically that African immigrants in France are significantly less likely to live in a building owned by a single landlord. This increases the probability that African immigrants live in public housing in localities with more single-landlord private apartment blocks.

[Fr] Les normes comptables IFRS ont intégré dans le bilan des banques l'essentiel des instruments financiers dérivés que nous considérons ici sous le terme de « hors-bilan », au prix d'une certaine invisibilité de leur « effet de levier ». Nous décrivons l'activité des banques de financement et d'investissement et montrons que ces instruments dérivés correspondent à une fonction d'intermédiation du risque dans l'économie où les banques ne « portent » pas ce risque au bilan, contrairement au métier bancaire traditionnel de « transformation ». Nous décrivons la banque comme une source d'« accroissement des possibles de la taille du marché » que nous définissons au préalable d'une manière générale. Une telle source, comme toute innovation, est synonyme de risque. Le « hors-bilan » bancaire apparaît dans ce cadre comme un effet de levier sans limite naturelle. Nous étudions alors ce que pourraient être des fiscalités adaptées à trois objectifs différents : corriger et capter les rentes, limiter le risque systémique, maîtriser l'« accroissement des possibles ». Une assiette considérant une mesure des engagements en valeur absolue associés aux positions sur les produits dérivés, dans le bilan des banques, paraît pertinente pour limiter l'accroissement des possibles et, partant de là, le risque.
[Eng] The accounting standard IRFS have integrated the bulk of derivatives (the off-balance sheet in this paper) in the balance sheet of the banks at the cost of masking their leverage effect. We describe the bank activity and we show that these derivatives correspond to a financial intermediation function of the banking system, which supplements the standard lending role of banks. We show that the banking activity naturally increases the possibility set of the capital market that we define in general terms. As all innovations, this increase bears additional risk. The off-balance sheet appears in this framework as bringing a leverage effect without natural limit. We study what could be the role of different types of taxes: first, correcting and capturing the rents, second, limiting the systemic risk, third, mastering the “growth of the feasible set”. A tax base consisting in financial liabilities (in absolute value) associated to positions on financial derivatives may be viewed as well-focused to limit the growth of the possibility set and therefore of the risk.

Equality of opportunity is usually defined as a situation where the effect of circumstances on outcome is nullified (compensation principle) and effort is rewarded (reward principle). We propose a new version of the reward principle based on the idea that effort deserves reward for it is costly. We show that luck can be introduced in two ways in the definition of these principles, depending on whether the correlation between luck and circumstances should be nullified and whether the correlation between luck and effort should be rewarded. In this regard, the timing of luck with respect to effort decisions is crucial, as is exemplified by moral hazard where effort choice influences the lottery of future uncertain events.