HEC Paris

About: HEC Paris is a education organization based out in Jouy-en-Josas, France. It is known for research contribution in the topics: Market liquidity & Entrepreneurship. The organization has 584 authors who have published 2756 publications receiving 104467 citations. The organization is also known as: Ecole des Hautes Etudes Commerciales & HEC School of Management Paris.

Influence of skin colour on the detection of cutaneous erythema and tanning phenomena using reflectance spectrophotometry.

Abstract: Background/purpose: This research aims at assessing the influence of baseline skin colour on the ability of reflectance spectrophotometry to detect cutaneous erythema induced by a low concentration of methyl nicotinate (2.5 mM) (first objective), and to detect tanning induced by ultraviolet rays (UVA+UVB) at infra-erythemal doses (second objective). Methods: Two independent studies were conducted to reach their respective objectives, on 27 women for the first study and on 12 women for the second study. Skin colour measurements were expressed in two different ways: percentages of reflected light at increasing wavelengths λ (400 nm<λ<700 nm, at 10 nm intervals), and chromametric coordinates of the CIELab 1976 system and individual typological angle (ITA°). Partial least squares discriminant analysis was performed to identify percentages of reflected light that allow the discrimination of the observations obtained after methyl nicotinate application from those obtained after water application (control). The same method was used for the discrimination of the measurements obtained after UV irradiation from those obtained before UV irradiation (control). Results and discussion: The cutaneous erythema induced by a low concentration of methyl nicotinate was detected only in subjects with fair to very fair skin defined by ITA≥40°. The assumption is that in the darkest skins, the emitted light is mainly absorbed by the melanin in the epidermis. Otherwise, after UV irradiation, the tanning was detectable only for individuals with fair to dark skin defined by ITA <50°. This can be explained by the fact that UV stimulation of the fairest skin subjects, known to be melano-compromised individuals, can only produce a weak tanning that our study did not succeed in detecting.

Does ownership matter in private equity? The sources of variance in buyouts' performance

Abstract: We study the impact of ownership on firm performance in an unexplored governance context: private equity (PE) firms and the buyouts in which they invest. We employ a multiple-membership, cross-classified, multilevel model on a unique database of 6,950 buyouts realized by 255 PE firms between 1973 and 2008 in 77 countries. The results document a significant PE firm effect (4.6%), the importance of which grows as time passes. We then study three contingencies that increase the importance of the PE firm effect: (1) value addition vs. selection strategies; (2) developed vs. emerging economies; and (3) economic downturns. Our findings shed new light on the sources of variance in buyouts' performance.

The Competitive Effect of a Bank Megamerger on Credit Supply

Abstract: We examine how the merger between two European megabanks affects credit supply to small and medium-sized businesses. Using loan-level and firm-level data, we exploit variation in the merging banks' market overlap to identify the competition effect of the merger. We find that the merged bank decreases the supply of credit to existing firms and new firms. This effect is not offset by other banks increasing their lending, leading to an overall decline in bank credit. This reduction in credit supply is associated with higher firm exit. However, for continuing firms, the merger has no adverse effects on investment and employment.

What Are Analytic Narratives

Abstract: The recently born expression "analytic narratives" refers to studies that have appeared at the boundaries of history, political science, and economics. These studies purport to explain specific historical events by combining the usual narrative way of historians with the analytic tools that economists and political scientists find in rational choice theory. Game theory is prominent among these tools. The paper explains what analytic narratives are by sampling from the eponymous book Analytic Narratives by Bates, Greif, Levi, Rosenthal, and Weingast (1998) and covering one outside study by Mongin (2008). It first evaluates the explanatory performance of the new genre, using some philosophy of historical explanation and then checks its discursive consistency, using some narratology. The paper concludes that analytic narratives can usefully complement standard narratives in historical explanation, provided they specialize in the gaps that these narratives reveal and that they are discursively consistent, despite the tension that combining a formal model with a narration creates. Two expository modes, called alternation and local supplementation, emerge from the discussion as the most appropriate ones to resolve this tension

Approval voting and Arrow’s impossibility theorem

Abstract: Approval voting has attracted considerable attention in voting theory, but it has rarely been investigated in an Arrovian framework of collective preference (”social welfare”) functions and never been connected with Arrow’s impossibility theorem. The article explores these two directions. Assuming that voters have dichotomous preferences, it first characterizes approval voting in terms of its collective preference properties and then shows that these properties become incompatible if the collective preference is also taken to be dichotomous. As approval voting and majority voting happen to share the same collective preference function on the dichotomous domain, the positive result also bears on majority voting, and is seen to extend May’s and Inada’s early findings on this rule. The negative result is a novel and perhaps surprising version of Arrow’s impossibility theorem, because the axiomatic inconsistency here stems from the collective preference range, not the individual preference domain.