Parité de pouvoir d'achat | EPFL Graph Search

La parité de pouvoir d'achat (PPA) (on parle de valeurs mesurées en parité de pouvoir d'achat) est une méthode utilisée en économie pour établir une comparaison, entre pays, du pouvoir d'achat des devises nationales, ce qu’une simple utilisation des taux de change ne permet pas de faire. Explications Le pouvoir d'achat d’une quantité donnée d’argent dépend en effet du coût de la vie, c’est-à-dire du niveau général des prix. La PPA permet de mesurer combien une devise permet d’acheter de biens et services dans chacune des zones que l’on compare. Les économistes forment un « panier » normalisé de biens et de services, dont le contenu peut être sujet à discussion (à ce sujet, voir ). La monnaie couramment utilisée comme référence est le dollar américain, pris à une année donnée. Lois de prix unique (LPU) et parité du pouvoir d'achat (PPA) Dans un marché global et unifié, sans coûts de transport, les produits identiques ont tous le même prix au même instant et à

The Economics of Sharing Markets

Maryam Razeghian Jahromi

Sharing and redistributing assets between individuals has become a noticeable part of the economy. Ownership is no longer the sole mode of consumption and consumers have the option of choosing between ownership and access-based consumption. This change in the consumer behaviour creates both threats and opportunities for the incumbent firms. In this dissertation, techniques from microeconomics and game theory are utilized to investigate market equilibrium in presence of sharing markets. We focus on the peer-to-peer sharing of rival goods with economic motivations. Chapter 2 provides a robust mathematical model that captures the equilibrium dynamics in peer-to-peer markets. We provide a closed-form solution for the S-shaped evolution of asset sharing, with price-adjustment delays and transaction costs. Chapter 3 studies the effects of sharing markets on the purchase price and durability of new products. We show that the pricing and product design can serve as a strategic tool to exploit or mitigate the impact of a peer-to-peer economy on the manufacturer's profit. Adjusting the built-in durability allows the firm to either defeat sharing (by shutting down the sharing market) or promote it (by offering durable and shareable objects). Chapter 4 develops a model to addresses the question of the firm's optimal adaptation of business model in the presence of sharing markets. We investigate second-degree price discrimination in the form of offering rental and/or purchase options and find that the population's sharing propensity is a major determinant of the firm's optimal selling strategy. As the population's sharing propensity increases, the firm moves from unbundling (exclusive renting), via mixed bundling (selling and renting upon demand), to pure bundling (exclusive selling).

EPFL2017

A pilot study on eliciting human operations decision in purchasing and measuring their impact on supply chain efficiency

Yvonne Badulescu, Rémy Glardon, Souleïman Naciri, Min-Jung Yoo

This paper presents a methodology for eliciting the behavioural model of purchasers' decision-making in a supply chain environment. The objective of the work is to explicitly describe the relationship between a human user's behaviour and the resulting performance in inventory level and service satisfaction. The key research findings include: (i) How to identify a categorised pattern of a human decision model, particularly concerning purchasing operations; and (ii) Which metrics would be relevant in the objective of carrying out a quantitative analysis on decision behaviour. The order placement behaviour is studied as one of daily operational decisions. The work demonstrates how to analyse a potential relationship between each category of behaviour and selected measures of supply chain performance, i.e., average inventory level and delivery satisfaction. We developed a specialised tool for supply chain simulation aimed at collecting data such as information consultations and decision-making actions of purchasing operations. The methodology is composed of sub-processes, such as data log file generation, data parsing and information generation, behaviour profile identification through clustering, and the analysis of supply performance regarding each category of decision-making behaviour. Through experimentation with industrial purchasing agents, we validated the effectiveness of the approach and demonstrated how to achieve a quantitative analysis of decision making behaviour and its impact on supply performance. (C) 2017 Elsevier Ltd. All rights reserved.

Pergamon-Elsevier Science Ltd2017

A Study of Synthesis & [and] Performance of Flame-Made Semiconducting BiVO4 Nanoparticles for the Photocatalytic Degradation of Aqueous Organic Pollutants

Nikola Castillo

Semiconductor photocatalysis is an Advanced Oxidation Technology that uses light as a source of energy to accelerate the degradation of harmful organic pollutants. Current research addresses the development of photocatalysts capable of harvesting visible light (Chapter 1). Bismuth vanadate (BiVO4) is a semiconductor that can absorb visible light up to 500 nm. It has been successfully tested for the oxidation of water and some dyes. So far, this material has been synthesized with low specific surface areas (SSA). Flame Spray Synthesis is a cost-effective method for the synthesis of nanoparticles and can be easily scaled up. The Flame Spray Synthesis of BiVO4 nanoparticles is described in detail. Careful adjustment of the process parameters allowed to control particle size and crystallinity of the as-prepared BiVO4 powders. Temperature of the collection site was found to hold a critical role on the control of these two properties (Chapter 3). Photocatalytic activity of the as-synthesized powders was then evaluated for the degradation of the Methylene Blue dye under visible-light irradiation. Photocatalyst properties controlled by synthesis parameters were confronted with their photocatalytic activity. It was found that both crystalline and amorphous powders could carry out the N-demethylation of Methylene Blue. Higher SSA lead to higher activity. A crystalline sample with moderate SSA was also found to degrade phenol to some extent at acidic pH but was subject to deactivation. Addition of different electron acceptors improved its photocatalytic activity. In particular, hydrogen peroxide (H2O2) could be used as a powerful yet rapidly consumed electron scavenger that enabled the degradation of phenol and dichloroacetate at neutral pH (Chapter 4). Advanced electrochemical and photochemical methods gave evidence of the poor reducing power of conduction-band electrons of BiVO4. Besides, the presence of deep traps associated with the change of coordination geometry of vanadium surface atoms upon photoexcitation has been correlated with the apparent photocatalytic activity of flame-made BiVO4 at pH 2. Finally, a mechanism involving the regneration of MB after its reduction when used as an electron acceptor has been proposed (Chapter 5). The flame spray synthesis of BiVO4 might be developed to produce high-SSA amorphous photocatalysts for the selective N-demethylation of Methylene Blue. Regarding the development of novel photocatalysts, the understanding of the role of the atomic surface structure should become a priority to increase their activity.

EPFL2011

A Study of Synthesis & [and] Performance of Flame-Made Semiconducting BiVO4 Nanoparticles for the Photocatalytic Degradation of Aqueous Organic Pollutants

Nikola Castillo

EPFL2011