Économies d’échelle et de gamme dans les coopératives de services financiers : une approche non paramétrique (DEA)

Lorsque des économies d’échelle et de gamme sont simultanément présentes, le regroupement des établissements tend à réduire les coûts. Puisque de nombreuses études empiriques ont déjà établi que les coûts des banques tendent à devenir proportionnels au-delà d’une certaine taille, il y aurait une limite à ces économies d’échelle et de gamme dans l’industrie bancaire. Nous étudions si l’important processus de fusions des caisses Desjardins et des caisses acadiennes entrepris en 1998 les a poussées au-delà de leur seuil minimal d’efficacité. Une analyse initiale à l’aide du lissage exponentiel montre que le coût moyen d’opération cesse de diminuer lorsque l’actif d’une caisse atteint 250 millions de dollars. Nous effectuons cependant une analyse plus formelle à l’aide de la méthode du Data envelopment analysis (DEA) et utilisons un résultat de Fortin et Leclerc (2006) pour décomposer les économies de gamme en efficacité d’échelle et en une mesure de convexité de la fonction de production. En combinant cette décomposition avec les méthodes maintenant bien connues pour calculer l’efficacité d’échelle avec le DEA, nous montrons que la plupart des fusions ont amené la caisse fusionnée à une taille telle qu’elle se situe en situation de rendement d’échelle décroissant. La recherche de la taille optimale ne semble donc pas être la première préoccupation dans la décision de fusion.When both economies of scale and scope are simultaneously observed, merger tends to reduce costs. Numerous empirical studies have already established that beyond a certain size, banks’ costs tend to become proportional, thus establishing a limit to economies of scale and scope. We verify if the important merger process of Desjardins and Acadian credit unions started in 1998 pushed them beyond the more efficient scale size. An initial analysis, using exponential smoothing, show that the average operating cost stops decreasing when the asset reaches 250 million Canadian dollars. A more formal analysis, using a Data envelopment analysis model is applied to the data set. Our empirical approach applies the method proposed by Fortin & Leclerc (2006) to decompose economies of scope into scale efficiency and a measure of the convexity of the production function. The search for optimal size does not seem to be the first concern in the decision to merge

Recent progress on indoor organic photovoltaics : from molecular design to production scale

Recently, indoor photovoltaics have attracted much interest for their ability to power small electronic devices and sensors, especially with the growth of the Internet of Things (IoT). Due to their absorption covering ambient emission spectra and tunable electronic structures, π-conjugated polymers and small molecules are well-suited for these applications. Among many benefits, including their ink processability, lightweight and flexibility; indoor organic photovoltaics (IOPVs) show power conversion efficiencies (PCE) over 26%. It represents a power output over 30 μW cm-2 under office light (500 lux), which is sufficient to operate many electronic devices and sensors with a relatively small photovoltaic area. This focus review highlights the major advances in the material design for IOPVs and includes some industrial insights to reach the production scale criteri

Déterminants du prix réel des logements au Canada

In order to identify the variables influencing the Canadian housing market, we estimate a structural model on annual data from 1956 to 2001. This model simultaneously explains the behaviour of the real average housing price and the change in the housing stock as measured by the number of housing units. Four variables are significant in the price equation: real per-capita income, nominal interest rate on residential 5-years mortgage loans, population growth in the 25 to 54 age group, and housing stock. As to the housing stock equation, the only significant variables are real housing price and changes in real per-capita income. The real price dropped during the recessions of 1981-82 and 1990-92 and remained low during the rest of the 90s. The stagnation of the housing market observed during the last decade resulted from a slower population growth and a sluggish economy. The only favourable impact came from the drop in the interest rates. The model’s price forecasts for the next fifteen years do not encompass price decreases because the trend increase in real income will more than offset the impact of the slower population growth. Afin d’identifier quelles variables ont affecté l’équilibre du marché du logement au Canada, nous estimons un modèle structurel sur des données annuelles agrégées de 1956 à 2001. Le modèle permet d’expliquer l’évolution du prix moyen et du nombre d’unités de logement. Trois variables exercent une influence significative sur le prix réel, soit le revenu réel par personne adulte, le taux d’intérêt nominal sur les prêts hypothécaires à l’habitation à 5 ans et la croissance de la population de 25 à 54 ans. Quant à la construction de nouveaux logements, la seule influence exogène provient du prix réel du logement. Le prix réel a fortement baissé pendant les récessions de 1981-82 et 1990-92 et s’est maintenu bas pendant tout le reste de la décennie quatre-vingt-dix. Le ralentissement de la croissance de la population a fortement contribué au marasme du marché immobilier pendant la dernière décennie, le ralentissement de la croissance du revenu réel par habitant jouant également un rôle important. Seule la baisse des taux d’intérêt a permis de maintenir un certain dynamisme sur ce marché pendant cette période. Les projections pour les quinze prochaines années ne laissent cependant pas entrevoir de baisses ultérieures de prix.

Économies d’échelle et de gamme dans les Caisses Desjardins

Nous utilisons les données comptables de 1 073 caisses populaires et d’économies Desjardins du Québec pour estimer une fonction de coût translogarithmique multiproduits dans le but de tester la présence d’économies d’échelle et de gamme. En utilisant l’approche par la production, nous définissons six catégories de produits, trois sortes d’intrants et trois variables de contrôle. Ces variables permettent de mesurer l’hétérogénéité de coûts provenant de la croissance à court terme de l’actif, de la densité d’occupation du sol et de la richesse de la clientèle. Nos résultats montrent que l’élasticité du coût par rapport à la production est de 0,98 et significativement inférieure à l’unité. Il y a donc de faibles économies d’échelle. Les économies de gamme semblent nettement plus importantes puisque nos estimés suggèrent que la production jointe permet de réduire les coûts d’opération de près de 50 %.Using accounting data from 1,073 Caisses populaires et d’économie Desjardins, we estimated a translogarithmic multi-product cost function enabling us to test for economies of scale and scope. Using the production approach, we defined six products, three inputs and three control variables to capture the cost heterogeneity stemming from short-term asset growth, localization of activities and clients' average wealth. We detected global scale economies, the output elasticity of the cost function being 0.98 and statistically less than one. However, global scope economies are much more important since the joint production allows for a cost savings of almost 50 %

Économies d’échelle et de gamme dans les Caisses Desjardins

Using accounting data from 1,073 Caisses populaires et d’économie Desjardins, we estimated a translogarithmic multi-product cost function enabling us to test for economies of scale and scope. Using the production approach, we defined six products, three inputs and three control variables to capture the cost heterogeneity stemming from short-term asset growth, localization of activities and clients' average wealth. We detected global scale economies, the output elasticity of the cost function being 0.98 and statistically less than one. However, global scope economies are much more important since the joint production allows for a cost savings of almost 50 %. Nous utilisons les données comptables de 1 073 caisses populaires et d’économies Desjardins du Québec pour estimer une fonction de coût translogarithmique multiproduits dans le but de tester la présence d’économies d’échelle et de gamme. En utilisant l’approche par la production, nous définissons six catégories de produits, trois sortes d’intrants et trois variables de contrôle. Ces variables permettent de mesurer l’hétérogénéité de coûts provenant de la croissance à court terme de l’actif, de la densité d’occupation du sol et de la richesse de la clientèle. Nos résultats montrent que l’élasticité du coût par rapport à la production est de 0,98 et significativement inférieure à l’unité. Il y a donc de faibles économies d’échelle. Les économies de gamme semblent nettement plus importantes puisque nos estimés suggèrent que la production jointe permet de réduire les coûts d’opération de près de 50 %.

Salt-induced thermochromism of a conjugated polyelectrolyte

We report here the photophysical properties of a water-soluble conjugated polythiophene with cationic side-chains. When dissolved in aqueous buffer solution (PBS, phosphate buffered saline), there is ordering of the polymer chains due to the presence of the salts, in contrast to pure water, where a random-coil conformation is adopted at room temperature. The ordering leads to a pronounced colour change of the solution (the absorption maximum shifts from 400 nm to 525 nm). Combining resonance Raman spectroscopy with density functional theory computations, we show a significant backbone planarization in the ordered phase. Moreover, the ratio of ordered phase to random-coil phase in PBS solution, as well as the extent of intermolecular interactions in the ordered phase, can be tuned by varying the temperature. Femtosecond transient absorption spectroscopy reveals that the excited- state behaviour of the polyelectrolyte is strongly affected by the degree of ordering. While triplet state formation is favoured in the random-coil chains, the ordered chains show a weak yield of polarons, related to interchain interactions. The investigated polyelectrolyte has been previously used as a biological DNA sensor, based on optical transduction when the conformation of the polyelectrolyte changes during assembly with the biomolecule. Therefore, our results, by correlating the photophysical properties of the polyelectrolyte to backbone and intermolecular conformation in a biologically relevant buffer, provide a significant step forward in understanding the mechanism of the biological sensing

Detection of target DNA using fluorescent cationic polymer and peptide nucleic acid probes on solid support

BACKGROUND: Nucleic acids detection using microarrays requires labelling of target nucleic acids with fluorophores or other reporter molecules prior to hybridization. RESULTS: Using surface-bound peptide nucleic acids (PNA) probes and soluble fluorescent cationic polythiophenes, we show a simple and sensitive electrostatic approach to detect and identify unlabelled target nucleic acid on microarray. CONCLUSION: This simple methodology opens exciting possibilities for applied genetic analysis for the diagnosis of infections, identification of genetic mutations, and forensic inquiries. This electrostatic strategy could also be used with other nucleic acid detection methods such as electrochemistry, silver staining, metallization, quantum dots, or electrochemical dyes

Structural and photophysical templating of conjugated polyelectrolytes with single-stranded DNA

A promising approach to influence and control the photophysical properties of conjugated polymers is directing their molecular conformation by templating. We explore here the templating effect of single-stranded DNA oligomers (ssDNAs) on cationic polythiophenes with the goal to uncover the intermolecular interactions that direct the polymer backbone conformation. We have comprehensively characterized the optical behavior and structure of the polythiophenes in conformationally distinct complexes depending on the sequence of nucleic bases and addressed the effect on the ultrafast excited-state relaxation. This, in combination with molecular dynamics simulations, allowed us a detailed atomistic-level understanding of the structure−property correlations. We find that electrostatic and other noncovalent interactions direct the assembly with the polymer, and we identify that optimal templating is achieved with (ideally 10−20) consecutive cytosine bases through numerous π-stacking interactions with the thiophene rings and side groups of the polymer, leading to a rigid assembly with ssDNA, with highly ordered chains and unique optical signatures. Our insights are an important step forward in an effective approach to structural templating and optoelectronic control of conjugated polymers and organic materials in general

Exciton Formation, Relaxation, and Decay in PCDTBT

The nature and time evolution of the primary excitations in the pristine conjugated polymer, PCDTBT, are investigated by femtosecond-resolved fluorescence up-conversion spectroscopy. The extensive study includes data from PCDTBT thin film and from PCDTBT in chlorobenzene solution, compares the fluorescence dynamics for several excitation and emission wavelengths, and is complemented by polarization-sensitive measurements. The results are consistent with the photogeneration of mobile electrons and holes by interband π−π* transitions, which then self-localize within about 100 fs and evolve to a bound singlet exciton state in less than 1 ps. The excitons subsequently undergo successive migrations to lower energy localized states, which exist as a result of disorder. In parallel, there is also slow conformational relaxation of the polymer backbone. While the initial self-localization occurs faster than the time resolution of our experiment, the exciton formation, exciton migration, and conformational changes lead to a progressive relaxation of the inhomogeneously broadened emission spectrum with time constants ranging from about 500 fs to tens of picoseconds. The time scales found here for the relaxation processes in pristine PCDTBT are compared to the time scale (<0.2 ps) previously reported for photoinduced charge transfer in phase-separated PCDTBT:fullerene blends (Phys. Rev. B 2010, 81, 125210). We point out that exciton formation and migration in PCDTBT occur at times much longer than the ultrafast photoinduced electron transfer time in PCDTBT:fullerene blends. This disparity in time scales is not consistent with the commonly proposed idea that photoinduced charge separation occurs after diffusion of the polymer exciton to a fullerene interface. We therefore discuss alternative mechanisms that are consistent with ultrafast charge separation before localization of the primary excitation to form a bound exciton