Pouvoir de marché et part du travail

This paper leverages a novel and comprehensive database on French firms from 1966 to 2016 to document important facts about secular trends in market power and labor shares, especially the role of market power in explaining variations of the aggregate labor share, as opposed to other technological factors. To do so, we follow the literature and rely on measures of industry concentration and firm level markups as proxies of market power. We find first that concentration has increased since the beginning of the 1980s in France, that the distribution of labor shares shifted upwards and that those two facts are correlated at the industry level. Second, aggregate markups increased slightly, but firm level markups decreased markedly. We find that the rise of concentration is correlated with a downward shift of the markup distribution, suggesting that the two measures might imperfectly capture different dimensions of market power. Third, larger firms have higher markups and lower labor shares. To sum up, larger firms with lower labor shares and higher markups gained market shares, even more so in industries where firm level labor shares increased and markups decreased most. From a macro point of view, the relative stability of the aggregate labor share in France can be decomposed into a small negative contribution of the aggregate markup, and a small positive contribution of aggregate technology, but from a micro point of view, reallocation contributed negatively, firm level markups contributed positively, and the contribution of technology was negligible

Measuring the State of ECN Readiness in Servers, Clients, and Routers

Proceedings of the Eleventh ACM SIGCOMM/USENIX Internet Measurement Conference (IMC 2011), Berlin, DE, November 2011.Better exposing congestion can improve traffic management in the wide-area, at peering points, among residential broadband connections, and in the data center. TCP's network utilization and efficiency depends on congestion information, while recent research proposes economic and policy models based on congestion. Such motivations have driven widespread support of Explicit Congestion Notification (ECN) in modern operating systems. We reappraise the Internet's ECN readiness, updating and extending previous measurements. Across large and diverse server populations, we find a three-fold increase in ECN support over prior studies. Using new methods, we characterize ECN within mobile infrastructure and at the client-side, populations previously unmeasured. Via large-scale path measurements, we find the ECN feedback loop failing in the core of the network 40\% of the time, typically at AS boundaries. Finally, we discover new examples of infrastructure violating ECN Internet standards, and discuss remaining impediments to running ECN while suggesting mechanisms to aid adoption

The Growing Complexity of Internet Interconnection

End-to-End (E2E) packet delivery in the Internet is achieved through a system of interconnections between heterogeneous entities called Autonomous Systems (ASes). The initial pattern of AS interconnection in the Internet was relatively simple, involving mainly ISPs with a balanced mixture of inbound and outbound traffic. Changing market conditions and industrial organization of the Internet have jointly forced interconnections and associated contracts to become significantly more diverse and complex. The diversity of interconnection contracts is significant because efficient allocation of costs and revenues across the Internet value chain impacts the profitability of the industry. Not surprisingly, the challenges of recovering the fixed and usage-sensitive costs of network transport give rise to more complex settlements mechanisms than the simple bifurcated (transit and peering) model described in many earlier analyses of Internet interconnection (see BESEN et al., 2001; GREENSTEIN, 2005; or LAFFONT et al., 2003). In the following, we provide insight into recent operational developments, explaining why interconnection in the Internet has become more complex, the nature of interconnection bargaining processes, the implications for cost/revenue allocation and hence interconnection incentives, and what this means for public policy. This paper offers an abbreviated version of the original paper (see FARATIN et al., 2007b).internet interconnection, economics, public policy, routing, peering.

QUANTITATION AND IMMUNOCYTOCHEMICAL LOCALIZATION OF HUMAN SKIN COLLAGENASE IN BASAL CELL CARCINOMA

Human skin collagenase was quantitated by radioimmunoassay in 21 basal cell carcinomas. Immunoreactive collagenase protein was found to be approximately 2-fold greater in extracts of these tumors than in extracts of normal skin, suggesting that this enzyme may be important in the pathogenesis of soft tissue destruction in vivo. To further define the role of collagenase in such destruction, immunofluorescent staining with specific antiserum to human skin collagenase was used to localize collagenase in the basal cell carcinomas. The enzyme was found only in the stromal elements surrounding the tumor islands. No staining of the epithelial components of the basal cell carcinomas was found. These findings suggest that the normal connective tissue elements may have been stimulated to produce an increased amount of collagenase and emphasize the importance of epithelial-stromal interaction in soft tissue invasiveness

THE SOLID SOLUBILITY AND CONSTITUTION OF YTTRIUM IN IRON-20 TO 40 w/o CHROMIUM ALLOYS

The solid solubility of yttrium in iron-20 to 40 wt.% chromium alloys was determined by metallographic techniques and found to be extremely small. At 1320 deg C, the maximum solubility is about 0.12 wt. a yttrium. Study of iron- rich alloys of the iron-yttrium system shows that the compound YFe/sub 5/ exists. A eutectic occurs between iron and YFe/sub 5/ at 1257 deg C. The constitution of iron - 20 to 40 wt.% chromium-yttrium alloys ccntaining less than 6 wt.% yttrium was studied between 1250 and 600 deg C. It was found that, upon exceeding the solubility limit, YFe/sub 5/ is formed and cccurs in conjunction with alpha iron - chromium. At about 900 deg C and above 615 deg C, if more than 6 wt.% yttrium is present in the iron-35 wt.% chromium alloy and more than 3 wt. % in iron-40 wt.% chromium alloy, YFe/sub 4/ forms to give a three-phase field of alpha plus YFe/sub 5/ plus YFe/sub 4/. The upper yttrium limit of this phase field was not determined. At 815 deg C, sigma phase forms in the iron - chromium system and comes into equilibrium with YFe/sub 5/. (auth

Assessing the inclusiveness of growth in Africa: Evidence from Cameroon, Senegal, and Tanzania

In this study, we assess the inclusiveness of growth by tracking the yearly percentage change in the household consumption of individuals over different growth spells in Cameroon, Senegal, and Tanzania. With cross-sectional data, we track the consumption of groups of individuals that share similar time-invariant characteristics, consistent with the pseudo-panel methodology. When the panel data are available, we track the consumption of each individual in order to generate the non-anonymous growth incidence curve. We find that the standard growth incidence curve does not always help to detect or to identify the winners and the losers from the growth process. In addition, the more educated individuals are not necessarily the ones that benefit from growth, except in Tanzania where growth is driven by the skill-intensive sectors. We also find significant losers from growth in Tanzania where the rate of inflation is very high compared to the other countries. Our methodology finds that 63 per cent of the population in Tanzania live in households whose real consumption expenditures fall during the growth spell

FTY720 Reduces Post-Ischemic Brain Lymphocyte Influx but Does Not Improve Outcome in Permanent Murine Cerebral Ischemia

BACKGROUND: The contribution of neuroinflammation and specifically brain lymphocyte invasion is increasingly recognised as a substantial pathophysiological mechanism after stroke. FTY720 is a potent treatment for primary neuroinflammatory diseases by inhibiting lymphocyte circulation and brain immigration. Previous studies using transient focal ischemia models showed a protective effect of FTY720 but did only partially characterize the involved pathways. We tested the neuroprotective properties of FTY720 in permanent and transient cortical ischemia and analyzed the underlying neuroimmunological mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: FTY720 treatment resulted in substantial reduction of circulating lymphocytes while blood monocyte counts were significantly increased. The number of histologically and flow cytometrically analyzed brain invading T- and B lymphocytes was significantly reduced in FTY720 treated mice. However, despite testing a variety of treatment protocols, infarct volume and behavioural dysfunction were not reduced 7d after permanent occlusion of the distal middle cerebral artery (MCAO). Additionally, we did not measure a significant reduction in infarct volume at 24 h after 60 min filament-induced MCAO, and did not see differences in brain edema between PBS and FTY720 treatment. Analysis of brain cytokine expression revealed complex effects of FTY720 on postischemic neuroinflammation comprising a substantial reduction of delayed proinflammatory cytokine expression at 3d but an early increase of IL-1β and IFN-γ at 24 h after MCAO. Also, serum cytokine levels of IL-6 and TNF-α were increased in FTY720 treated animals compared to controls. CONCLUSIONS/SIGNIFICANCE: In the present study we were able to detect a reduction of lymphocyte brain invasion by FTY720 but could not achieve a significant reduction of infarct volumes and behavioural dysfunction. This lack of neuroprotection despite effective lymphopenia might be attributed to a divergent impact of FTY720 on cytokine expression and possible activation of innate immune cells after brain ischemia