Ignorance promotes competition: An auction model with endogenous private valuations

We study a situation in which an auctioneer wishes to sell an object toone of N risk-neutral bidders with heterogeneous preferences. Theauctioneer does not know bidders preferences but has private informationabout the characteristics of the ob ject, and must decide how muchinformation to reveal prior to the auction. We show that the auctioneerhas incentives to release less information than would be efficient andthat the amount of information released increases with the level ofcompetition (as measured by the number of bidders). Furthermore, in aperfectly competitive market the auctioneer would provide the efficientlevel of information.

Cannabis use as a means of socialization?: new consumption patterns among heavy users

Purpose: After tobacco and alcohol, cannabis is the most used substance among adolescents in Switzerland. Our aim is to assess whether cannabis use has become an ordinary means of socialization. We hypothesize that cannabis consumption has become a normative, although still illegal, behavior. Methods: As part of a larger qualitative study aimed at assessing new ways [patterns] of cannabis consumption, 16 daily cannabis consumers (11 males) and 2 former heavy consumers (both females), aged 15 to 20 years, participated in interviews and focus groups. Data were transcribed verbatim and analyzed using Atlas.ti qualitative analysis software. Results: Most consumers define the beginning of their consumption as a moment when they made new friends. They commonly use cannabis in group settings, which encourages the belief that all adolescents use cannabis. Thus, cannabis is mainly identified as an everyday social act. Joints are smoked like cigarettes: at all times of the day, during or after school or work with peers, often starting at lunch break, and mostly in public places. Friends offer a joint in a group setting, much like beer in a bar, as a means of making contact. Consumption invariably increases while socializing on vacation: "During vacation, we smoke up to 10-15 joints a day; at the end we're just dead." Additionally, in order to obtain cannabis, consumers have to be part of the right networks; they generally have several dealers to assure their supply, buy and sell themselves, or practice group-buying. As a result, all friends or acquaintances of consumers are themselves cannabis users. For instance, 4 boys, who say they are best friends, always smoke together and that, in order to quit, "All four of us should say to ourselves, 'Okay, now, let's all stop smoking'. That would be the only solution. . .but it would be impossible!" The 2 former consumers state that when they started using cannabis, "I found myself little by little in a vicious circle where I saw only people who also smoked". When they quit, they separated from their group of friends: "Either you make new friends who don't smoke or you smoke." Conclusions: Discussions with consumers demonstrate a normative facet of cannabis consumption as part of teenage socialization. Consequently, cannabis consumers develop a significant dependency since a majority of their friends use cannabis and their consumption involves most of their daily social life. Our study highlights the need for clear messages about the harmful aspects of using this substance while also suggesting that cessation efforts should include helping users separate from their consumption milieu. Sources of Support: Dept. of Public Health of the canton of Vaud.

When in peril, retrench: Testing the portfolio channel of contagion

One plausible mechanism through which financial market shocks may propagate across countriesis through the impact that past gains and losses may have on investors risk aversion and behavior. This paper presents a stylized model illustrating how heterogeneous changes in investors risk aversion affect portfolio allocation decisions and stock prices. Our empirical findings suggest that when funds returns are below average, they adjust their holdings toward the average (or benchmark) portfolio. In so doing, funds tend to sell the assets of countries in which they were overweight , increasing their exposure to countries in which they were underweight. Based on this insight, the paper constructs an index of financial interdependence which reflects the extent to which countries share overexposed funds. The index helps in explain the pattern of stock market comovement across countries. Moreover, a comparison of this interdependence measure to indices of trade or commercial bank linkages indicates that our index can improve predictions about which countries are more likely to be affected by contagion from crisis centers.

Extracção de Areia na Praia de Calhetona (Ilha de Santiago, Cabo Verde) - Causas, Processos e Consequências

A extracção de areia nas praias do mar, nas bacias hidrográficas e nas encostas montanhosas, tem sido prática de muitas famílias cabo-verdianas. A Praia de Calhetona foi uma das que nos últimos anos sofreu degradação significativa, em função da apanha clandestina de areia, sem qualquer plano de extracção, destinada a construção civil. A extracção de areia, para vender ou para a autoconstrução, é efectuada em família por indivíduos, maioritariamente do sexo feminino, de baixa renda ou sem profissão remunerada. O processo de extracção de areia na Praia de Calhetona teve o seu ponto alto nos anos 80, diminuindo consideravelmente com a escassez de areia e implementação do Decreto – Lei nº 69/97, de 3 de Novembro, que visava disciplinar a exploração de inertes nas praias. Em face da pesquisa feita, baseada no estudo de caso, ficou expresso que os inquiridos implicados na actividade de extracção clandestina de areia correm riscos elevados para obterem lucros reduzidos. Quem efectivamente beneficia são os camionistas que compram esse inerte e o vendem pelo dobro do preço. Qualquer actividade de exploração de recursos naturais causa impactes sobre o espaço de actuação. No caso da Praia de Calhetona, observa-se o recuo da linha de costa, a quase ausência de areia e a desertificação de propriedades nas suas proximidades, para além dos impactes negativos sobre o turismo, a função balnear e a desova de tartaruga. Apesar de tudo, constata-se uma consciência generalizada dos impactes ambientais causados pelos inquiridos, os quais, no entanto, alegam que a extracção de areia é uma das alternativas para garantir a sobrevivência individual e das suas famílias.

A model of market-making

The two essential features of a decentralized economy taken intoaccount are, first, that individual agents need some informationabout other agents in order to meet potential trading partners,which requires some communication or interaction between theseagents, and second, that in general agents will face tradinguncertainty. We consider trade in a homogeneous commodity. Firmsdecide upon their effective supplies, and may create their ownmarkets by sending information signals communicating theirwillingness to sell. Meeting of potential trading partners isarranged in the form of shopping by consumers. The questions to beconsidered are: How do firms compete in such markets? And what arethe properties of an equilibrium? We establish existenceconditions for a symmetric Nash equilibrium in the firms'strategies, and analyze its characteristics. The developedframework appears to lend itself well to study many typicalphenomena of decentralized economies, such as the emergence ofcentral markets, the role of middlemen, and price-making.

Fair Housing and You, 2009

Federal Fair Housing Amendments Act was passed in 1988, making it illegal to refuse to rent or sell property to families because they have children. In 1992, the Iowa Civil Rights Act was amended to also prohibit discrimination against families with children.

Projecto de Simulação: Empresa Digital Tech

Em contexto de simulação, utilizando a plataforma Marketplace, foram colocados oito grupos, simulando serem empresas, a trabalhar num ambiente virtual de mercado. Neste, teriam de actuar como empresas produtoras e comercializadoras de computadores, exercendo todas as actividades de uma empresa real. O objectivo era avaliar o desempenho de cada grupo/empresa, vencendo quem tivesse o melhor Balanced Scorecard acumulado. O presente relatório refere-se a uma dessas empresas, nomeadamente, a Digital Tech. Abstract As a simulation, using the Marketplace Platform, eight groups were placed as companies operating in a virtual market. They would act as companies that produce and sell computers employing all the roles of a real company. The goal was to evaluate each group/company, to determine the winner with the best Accumulated Balanced Scorecard. This report is about one of these companies, The Digital Tech

Extracção de areia na praia de Calhetona (Ilha de Santiago, Cabo Verde): causas, processos e consequências

A extracção clandestina de areia, nas faixas costeiras e nos leitos das ribeiras, tem sido prática de muitos agregados familiares cabo-verdianos. Nas últimas décadas, a praia de Calhetona (Ilha de Santiago) foi um dos muitos locais que sofreram degradação ambiental significativa, devido à realização desta actividade sem quaisquer planos de extracção e de posterior recuperação das áreas degradadas. Este trabalho, através da conjugação de recolha de dados por inquérito, observação directa e pesquisa documental e bibliográfica, teve como objectivos a caracterização da comunidade (que habita no bairro de Ponta Calhetona) que se dedica à extracção de areia na praia de Calhetona, a descrição da dinâmica da actividade extractiva, a avaliação da percepção que a comunidade tem relativamente às consequências da sua actividade e a descrição do impacte ambiental resultante da extracção de areia. Da análise dos inquéritos, efectuados em Fevereiro de 2012, a 25 chefes de agregados familiares que efectuam a extracção de areia na praia de Calhetona, constata-se que estes são maioritariamente mulheres, predominantemente com idade compreendida entre os 40 e os 59 anos, domésticas, com baixa escolaridade, com famílias numerosas e/ou alargadas a seu cargo e dedicando-se à extração de areia à mais de 10 anos. Os inquiridos, face à situação de vulnerabilidade económica, à falta de emprego e à grande procura de areia para a construção civil, vêem nesta actividade uma fonte de rendimento. Contudo, o proveito obtido desta actividade difícil e potencialmente perigosa é reduzido. Quem efectivamente beneficia são os camionistas que compram a areia a quem procede à extracção e a vendem ao consumidor final pelo dobro do preço. Os inquiridos demonstram uma consciência generalizada dos diversos impactes ambientais negativos resultantes da sua actividade, mas alegam que a extracção de areia é uma das poucas alternativas existentes para providenciar o sustento dos seus agregados familiares. Com base na comparação do estado actual da praia de Calhetona com relatos de habitantes locais, relativos às características da mesma no passado, verifica-se que nos últimos 40-50 anos, desde que se iniciou a intensa extracção de areia nesta praia, o seu aspecto físico se degradou claramente. Essa degradação caracteriza-se principalmente pelo recuo da linha de costa, pela quase ausência de areia e pela salinização dos solos localizados nas proximidades da praia, para além dos consequentes impactes negativos sobre a desova das tartarugas e o turismo balnear.

Three essays on liquidity risk

Preface In this thesis we study several questions related to transaction data measured at an individual level. The questions are addressed in three essays that will constitute this thesis. In the first essay we use tick-by-tick data to estimate non-parametrically the jump process of 37 big stocks traded on the Paris Stock Exchange, and of the CAC 40 index. We separate the total daily returns in three components (trading continuous, trading jump, and overnight), and we characterize each one of them. We estimate at the individual and index levels the contribution of each return component to the total daily variability. For the index, the contribution of jumps is smaller and it is compensated by the larger contribution of overnight returns. We test formally that individual stocks jump more frequently than the index, and that they do not respond independently to the arrive of news. Finally, we find that daily jumps are larger when their arrival rates are larger. At the contemporaneous level there is a strong negative correlation between the jump frequency and the trading activity measures. The second essay study the general properties of the trade- and volume-duration processes for two stocks traded on the Paris Stock Exchange. These two stocks correspond to a very illiquid stock and to a relatively liquid stock. We estimate a class of autoregressive gamma process with conditional distribution from the family of non-central gamma (up to a scale factor). This process was introduced by Gouriéroux and Jasiak and it is known as Autoregressive gamma process. We also evaluate the ability of the process to fit the data. For this purpose we use the Diebold, Gunther and Tay (1998) test; and the capacity of the model to reproduce the moments of the observed data, and the empirical serial correlation and the partial serial correlation functions. We establish that the model describes correctly the trade duration process of illiquid stocks, but have problems to adjust correctly the trade duration process of liquid stocks which present long-memory characteristics. When the model is adjusted to volume duration, it successfully fit the data. In the third essay we study the economic relevance of optimal liquidation strategies by calibrating a recent and realistic microstructure model with data from the Paris Stock Exchange. We distinguish the case of parameters which are constant through the day from time-varying ones. An optimization problem incorporating this realistic microstructure model is presented and solved. Our model endogenizes the number of trades required before the position is liquidated. A comparative static exercise demonstrates the realism of our model. We find that a sell decision taken in the morning will be liquidated by the early afternoon. If price impacts increase over the day, the liquidation will take place more rapidly.

Disseny i implementació d'una web administrable i d'una aplicació per dispositius mòbils

En la societat en què vivim cada vegada agafen més importància les pàgines web, ja que és una eina d’informació molt útil i ràpida de consultar. Per això, no s’entén que una activitat empresarial sigui del tipus que sigui, no tingui representació a la xarxa. No és necessari que l’activitat en qüestió hagi de vendre productes a través d’Internet, sinó que simplement aquesta representació pot ajudar a donar a conèixer l’empresa i a ampliar la cartera de clients. De la mateixa manera, els dispositius mòbils també s’estan convertint en una eina important en la societat d’avui en dia i una bona aplicació pot aportar-te un avantatge en moltes de les feines diàries de les persones. D’aquestes idees sorgeix el projecte de fer la web i l’aplicació pel centre de fisioteràpia Fisioripoll. La web serviria per tenir un lloc a la xarxa on donar-se a conèixer i poder captar nous clients, i l’aplicació funcionaria com a eina pel propi centre, seria una espècie d’agenda electrònica per saber les hores que tens reservades els pròxims dies. Per aconseguir un bon funcionament de la web, s’ha demanat que la pàgina sigui administrable en els seus continguts. És a dir, que els propis gestors del centre puguin canviar els texts, les imatges dels diferents apartats i gestionar les reserves dels clients. En canvi, l’aplicació serà només una eina de consulta i no s’hauria de gestionar res. Per tal de dur a terme aquesta web s’ha tingut en compte utilitzar eines de programació de distribució lliure com és el llenguatge PHP, la base de dades MySQL, jQuery, el framework Phonegap per tal de poder construir una web i una aplicació amb cost de programari nul.

Stand Out In A Crowd! Merchandising Your Job Talents,

You want a job. And you believe that somewhere, some employer has precisely the job you want - one that fully utilizes your knowledge and abilities and provides challenge and opportunities for advancement. To find that job, you need to perform a well-planned job search. You have a product to sell - your knowledge, skills and experience . . . YOURSELF! What you need to know is how to market yourself most effectively. Whether you are just out of school and ready to start your career or looking for a new position after 20 years of experience, some of the techniques presented in this booklet may help you. NOTE: ENGLISH

Deciding the sale of a life policy in the viatical market: Implications on individual welfare

[cat] En aquest article, es presenta un model econòmic que permet determinar la venda o no d'una pòlissa de vida (total o en part) per part d'un assegurat malalt terminal en el mercat dels viatical settlements. Aquest mercat va aparèixer a finals de la dècada dels 80 a conseqüència de l'epidèmia de la SIDA. Actualment, representa una part del mercat dels life settlements. Les pòlisses que es comercialitzen en el mercat dels viaticals són aquelles on l'assegurat és malalt terminal amb una esperança de vida de dos anys o menys. El model és discret i considera només dos períodes (anys), ja que aquesta és la vida residual màxima que contempla el mercat. L'agent posseix una riquesa inicial que ha de repartir entre consum i herència. S'introdueix en primer lloc la funció d'utilitat esperada del decisor i, utilitzant programació dinàmica, es dedueix l'estratègia que reporta una utilitat més gran (no vendre/vendre (en part) la pòlissa en el moment zero/vendre (en part) la pòlissa en el moment ú). L'òptim depèn del preu de la pòlissa venuda i de paràmetres personals de l'individu. Es troba una expressió analítica per l'estratègia òptima i es realitza un anàlisi de sensibilitat.

Deciding the sale of a life policy in the viatical market: Implications on individual welfare

[cat] En aquest article, es presenta un model econòmic que permet determinar la venda o no d'una pòlissa de vida (total o en part) per part d'un assegurat malalt terminal en el mercat dels viatical settlements. Aquest mercat va aparèixer a finals de la dècada dels 80 a conseqüència de l'epidèmia de la SIDA. Actualment, representa una part del mercat dels life settlements. Les pòlisses que es comercialitzen en el mercat dels viaticals són aquelles on l'assegurat és malalt terminal amb una esperança de vida de dos anys o menys. El model és discret i considera només dos períodes (anys), ja que aquesta és la vida residual màxima que contempla el mercat. L'agent posseix una riquesa inicial que ha de repartir entre consum i herència. S'introdueix en primer lloc la funció d'utilitat esperada del decisor i, utilitzant programació dinàmica, es dedueix l'estratègia que reporta una utilitat més gran (no vendre/vendre (en part) la pòlissa en el moment zero/vendre (en part) la pòlissa en el moment ú). L'òptim depèn del preu de la pòlissa venuda i de paràmetres personals de l'individu. Es troba una expressió analítica per l'estratègia òptima i es realitza un anàlisi de sensibilitat.

Fair Housing For Families with Children

What’s wrong with this advertisement? This wording used to be very familiar in our daily newspaper ads. But the federal Fair Housing Amendments Act was passed in 1988, making it illegal to refuse to rent or sell property to families because they have children. In 1992, the Iowa Civil Rights Act was amended to also prohibit discrimination against families with children. The law defines a family with children as follows: One or more individuals under the age of 18 living with a parent, or with a person having legal custody  A designee of such parent or legal guardian  Persons who are expecting a baby or who are seeking legal custody of a child.