the interaction between shocks and institutions solve the OECD shocks and institutions solve the OECD Unemployment Puzzle ? A Theoritical and Empirical Appraisal.

This paper provides a theoretical and empirical appraisal of the shocks-institutions controversy as an explanation of unemployment heterogeneity in OECD countries. Since the influential work of Blanchard and Wolfers (2000), many studies have tried to explain the differences in the OECD unemployment rate as the result of interaction between shocks and labour market institutions. Modelling this interaction is viewed as a promising way for understanding the puzzle of unemployment disparities which can be explained by none of the two kinds of variables individually. Indeed, on the one hand, OECD countries have been affected by symmetric shocks and have nevertheless experienced different unemployment dynamics. On the other hand, before the 1970s, all these countries had low unemployment rates in spite of quite different labour market institutions. Using cross section data, these studies test a direct relationship between the unemployment rate, shocks and institutions and thus have the advantage of readily allowing for international comparisons. However, testing a reduced equation of the unemployment rate constitutes also their main drawback as they do not analyze formally the link between the unemployment rate and the wage determination process. As a consequence, empirical results are quite divergent among studies since they often lay on ad hoc specifications that may have little theoretical foundations.Equilibrium unemployment;Structural model;shock;labour market institutions;OECD;cross-section estimation;

REDUCTION DES APPORTS CUPRIQUES EN VITICULTURE BIOLOGIQUE:ETUDE DU LESSIVAGE FOLIAIRE SOUS SIMULATEUR DE PLUIE;

Le cumul de pluie reste le principal facteur explicatif du lessivage des produits cupriques étudiés (Héliocuivre et BB RSR Disperss)et donc le seul critère de renouvellement de la protection (hormis naturellement la vitesse de croissance). Les autres critères étudiés, répartition des pluies,intensité ou délai de 7 jours entre traitement et pluie se révèlent sans effet. Les 5 premiers millimètres de pluie sont ceux générant le plus de pertes, le taux de lessivage diminuant très rapidement au-delà.Environ 40% de la dose initiale reste présent après 50mm de pluie.La perte de cuivre est de nature hyperbolique. Les dynamiques de lessivage ont été modélisées

Etude des motivations et des satisfactions des patients d'un secteur rural ayant consulté un guérisseur

TOURS-BU Médecine (372612103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Improving Manufacturing Performance Through Process Change and Knowledge Creation

A model is introduced to guide a profit maximizing firm in its quest to enhance performance through process change. The key benefit sought from process change is a long term increase in effective capacity. However, realizing success from process change is not trivial. First, while process change may increase effective capacity in the long run, the disruptions during implementation typically reduce short term capacity. Second, competitive forces such as decreasing revenue streams and shrinking product life cycles complicate the implementation of process change. Third, while knowledge may enhance the ultimate benefits derived from process change, the correct timing and means of knowledge creation are difficult to discern. Lastly, a variety of trade-offs must be evaluated when selecting the particular process change to pursue. For example, choices range from hardware and software replacements to modification of manufacturing procedures. The model introduced here explicitly considers both the short term loss due to disruption and the long term gain in effective capacity associated with the process change. In addition, investments in the accumulation of knowledge are investigated for their potential to enhance process change effectiveness. Knowledge is generated from investment in preparation and training (learning-before-doing) and as a by-product of process change (learning-by-doing). Analysis of the model provides managerial recommendations for several key decisions relating to process change implementation including: (i) the selection of an appropriate process change alternative, (ii) the rate and timing for investment in process change, and (iii) the rate and timing for investment in preparation and training. New results are reported reflecting the important relationship between process change and knowledge. For example, we show that under certain conditions, a firm should optimally delay investment in process change until sufficient accumulation of knowledge is achieved. More generally, we identify conditions whereby investment in process change occurs at an increasing rate over time. This result is particularly important since it demonstrates a limitation of the existing literature where process change always occurs at a decreasing rate.process change, knowledge management, optimal control theory