The Portfolio Choice in Emergent Markets a Rational or a Behavioral Decision: a Cognitive Answer

The purpose of this study is to explore the relationship between the rational and the behavioral portfolio theories, two theories that describes the decision making process on the domain of portfolio choice, under investors' perception. This will offer a more realistic answer that describes the investors' decision on term of portfolio choice. Our sample contains 30 Tunisian investors who trade at the Tunisian stock exchange (BVMT). We introduce an approach based on cognitive mapping with a series of interviews. We combine both concepts that belong to the mean-variance and the behavioral approach and we explore the interactions between them. We introduce some new notions such as the zone of communication between the two cited theories and the variables of connection. We demonstrate that investors use the mean-variance theory of portfolio choice but they are affected by their cognitive biases and emotions when making their portfolio choice decision. Keywords: Mean-variance portfolio Choice, Behavioral Portfolio Choice, cognitive maps, areas of communication, concepts of connection

Mapping environmental pollution disclosures in Tunisia

The aim of this paper is to examine the mental models of actors in Tunisian firms with respect to the environmental pollution. The authors use a cognitive map to observe these mental diagrams and to visualize ways to conceptualize the environmental pollution and to understand this concept through the presentation and analysis of the cognitive maps of Tunisian firm’s actors. Each actor’s systematic exploration grid shows a balance of concepts that expresses their cognitive orientation. Thus, the authors visualize the concepts (variables) that structure the cognitive universe of the actors, which is projected in terms of influences and dependencies. This research provides some lines of thought about environmental and pollution reporting that should be explored further. The research can only help to launch a debate on corporate accountability and transparency

Investment cash flow sensitivity under managerial optimism: New evidence from NYSE panel data firms

Investment cash flow sensitivity constitutes one important block of the corporate financial literature. While it is well documented in standard corporate finance, it is still young under behavioral corporate finance. In this paper, we test the investment cash flow sensitivity among panel data of American industrial firms during 1999-2010. Using Q-model of investment (Tobin, 1969), we construct and introduce a proxy of managerial optimism following Malmendier and Tate (2005a) to show the impact of CEOs’ optimism in the relationship between investment and internal cash flow. Our results report a positive and significant coefficient of investment to cash flow for the full sample. While, on estimations of our model using sub-sample of more and less constrained firms, we find that the sensitivity exists stronger only for totally constrained group. We find also that board characteristics can reduce investment policy's distortions.La sensibilidad de la inversión al flujo de caja constituye un bloque importante de la literatura financiera corporativa. Aunque está bien documentada en las finanzas corporativas estándar, aún es reciente en las conductuales. En este artículo investigamos la sensibilidad de la inversión al flujo de caja en los datos de panel de compañías industriales estadounidenses durante el período 1999-2010. Utilizando un modelo Q de inversión (Tobin, 1969), construimos e introducimos una representación de optimismo empresarial según Malmendier y Tate (2005a) para mostrar el impacto del optimismo del director ejecutivo en la relación entre inversión y flujo de caja interno. Nuestros resultados revelan un coeficiente de inversión al flujo de caja positivo y significativo en toda la muestra. Mientras, sobre las estimaciones de nuestro modelo utilizando submuestras de compañías más y menos limitadas, descubrimos que la sensibilidad es más fuerte solo para el grupo totalmente limitado. También detectamos que las características del consejo directivo pueden reducir las distorsiones de la política de inversión

Investment cash flow sensitivity under managerial optimism: New evidence from NYSE panel data firms

Investment cash flow sensitivity constitutes one important block of the corporate financial literature. While it is well documented in standard corporate finance, it is still young under behavioral corporate finance. In this paper, we test the investment cash flow sensitivity among panel data of American industrial firms during 1999-2010. Using Q-model of investment (Tobin, 1969), we construct and introduce a proxy of managerial optimism following Malmendier and Tate (2005a) to show the impact of CEOs? optimism in the relationship between investment and internal cash flow. Our results report a positive and significant coefficient of investment to cash flow for the full sample. While, on estimations of our model using sub-sample of more and less constrained firms, we find that the sensitivity exists stronger only for totally constrained group. We find also that board characteristics can reduce investment policy's distortions.La sensibilidad de la inversi?n al flujo de caja constituye un bloque importante de la literatura financiera corporativa. Aunque est? bien documentada en las finanzas corporativas est?ndar, a?n es reciente en las conductuales. En este art?culo investigamos la sensibilidad de la inversi?n al flujo de caja en los datos de panel de compa??as industriales estadounidenses durante el per?odo 1999-2010. Utilizando un modelo Q de inversi?n (Tobin, 1969), construimos e introducimos una representaci?n de optimismo empresarial seg?n Malmendier y Tate (2005a) para mostrar el impacto del optimismo del director ejecutivo en la relaci?n entre inversi?n y flujo de caja interno. Nuestros resultados revelan un coeficiente de inversi?n al flujo de caja positivo y significativo en toda la muestra. Mientras, sobre las estimaciones de nuestro modelo utilizando submuestras de compa??as m?s y menos limitadas, descubrimos que la sensibilidad es m?s fuerte solo para el grupo totalmente limitado. Tambi?n detectamos que las caracter?sticas del consejo directivo pueden reducir las distorsiones de la pol?tica de inversi?n

CEO's personal characteristics, ownership and investment cash flow sensitivity: evidence from NYSE panel data firms

This study tries to extend previous works on behavioral corporate finance by examining the interaction between investment cash flow sensitivity and various CEO characteristics in either the existence or inexistence of managerial optimism. Using a Q-investment model and departing from a sample of 475 annual observations, our results highlight that CEO's financial education, CEO's ownership and their optimism bias can explain distortions in corporate investment policy since they affect investment cash flow's relationship.Este estudio trata de ampliar los trabajos previos sobre el comportamiento de la financiaci?n corporativa, mediante el examen de la interacci?n entre la sensibilidad del flujo de caja de inversi?n y las diversas caracter?sticas de los directores ejecutivos (CEO), en t?rminos de existencia o no existencia de un optimismo gerencial. Utilizando un modelo de inversi?n Q, y partiendo de una muestra de 475 observaciones anuales, nuestros resultados subrayan que la formaci?n financiera, la titularidad, y las tendencias del optimismo de los CEO pueden explicar las distorsiones de las pol?ticas de inversi?n corporativa, ya que estas afectan a la relaci?n del flujo de caja de inversi?n

CEO's personal characteristics, ownership and investment cash flow sensitivity: evidence from NYSE panel data firms

This study tries to extend previous works on behavioral corporate finance by examining the interaction between investment cash flow sensitivity and various CEO characteristics in either the existence or inexistence of managerial optimism. Using a Q-investment model and departing from a sample of 475 annual observations, our results highlight that CEO's financial education, CEO's ownership and their optimism bias can explain distortions in corporate investment policy since they affect investment cash flow's relationship.Este estudio trata de ampliar los trabajos previos sobre el comportamiento de la financiación corporativa, mediante el examen de la interacción entre la sensibilidad del flujo de caja de inversión y las diversas características de los directores ejecutivos (CEO), en términos de existencia o no existencia de un optimismo gerencial. Utilizando un modelo de inversión Q, y partiendo de una muestra de 475 observaciones anuales, nuestros resultados subrayan que la formación financiera, la titularidad, y las tendencias del optimismo de los CEO pueden explicar las distorsiones de las políticas de inversión corporativa, ya que estas afectan a la relación del flujo de caja de inversión

Antibacterial Screening of Origanum majorana L. Oil from Tunisia

International audienceTwo methods (agar diffusion and broth microdilution) were used to assess the antibacterial activity of Origanum majorana L. oil of Tunisian origin against 10 bacteria. The results showed that this oil was active against all of the tested strains. The most susceptible were Escherichia coli, Streptococcus A, Shigella dysenteria and Salmonella enteritidis. The least susceptible one was Pseudomonas aeruginosa

Environmental controlling factors of copepod communities in the Gulf of Tunis (south western Mediterranean Sea)

The copepod community structure and the distribution of the main groups of zooplankton were studied along an inshore-offshore gradient in the Gulf of Tunis during the rainy and dry seasons of 2007-2008. Hydrological parameters were also measured to assess the potential role of abiotic and biotic factors in the distribution of copepod species. The copepod community in the Gulf of Tunis comprises 86 species dominated by Paracalanus parvus, Clausocalanus lividus, Centropages kroyeri and Acartia clausi. Time had a greater influence than space (horizontal and vertical gradients) in shaping the copepod community structure with a significant influence of the seasons; winter (cold and rainy) resulted in hydrological conditions that were strongly different from those observed in summer (warm and dry). These hydrological differences were concomitant with changes in the community structure, with a high copepod diversity observed in winter while the summer period was characterized by a low specific richness and the dominance of a few species, Centropages kroyeri and Paracalanus parvus along the inshore-offshore gradient and Paracalanus aculeatus along the vertical. Canonical correspondence analysis showed that temperature, salinity and to a lesser extent chlorophyll a were the most important environmental factors structuring the copepod community. Interestingly, temperature and salinity showed a negative significant correlation with copepod specific richness. Competition with grazers (cladoceran) as well as top down control by predators (chaetognaths and siphonophors) were also identified as key factors for the copepod community structure

PHENOTYPIC VARIABILITY AND SEED YIELD OF JATROPHA CURCAS L. INTRODUCED TO TUNISIA

Volume: 110Start Page: 119End Page: 13

Phenotypic variability and seed yield of Jatropha curcas L. Introducen to Tunisia

Eight accessions of Jatropha curcas (six American and two African) were sown in the south of Tunisia (Gabès) to study its agricultural properties and development under local semi-arid conditions. Traits observed included general aspects of plant development (plant height, canopy circumference, number of nodes and seed yield); leaf characteristics (petiole length, limb length, limb width and foliar surface); and seed traits (size and shape). Morphological analysis of seeds included seed image area, perimeter, length/width ratio, circularity index and J index. This index reflects the similarity of seed images with an ellipse showing differences in seed shape between accessions. Jatropha curcas genotypes introduced in Tunisia are polymorphic, their seed yield is low and variable between genotypes. Seed morphology analysis gave an indication in relation with the productivity in some of the accessions. The comparative agronomic studies are crucial before early selection.Se sembraron en el sur de Túnez (Gabès) semillas de ocho accesiones de Jatropha curcas (seis americanas y dos africanas) para estudiar sus propiedades agrícolas y desarrollo en condiciones locales semiáridas. Los caracteres observados incluyen aspectos generales del desarrollo de planta (altura, circunferencia del follaje, número de nodos y producción de semillas); características de las hojas (longitud del peciolo, longitud del limbo, anchura del limbo y superficie foliar); y caracteres de la semilla (tamaño y forma). El análisis morfológico de las semillas incluyó el área de las imágenes, el perímetro, la relación longitud/anchura, el índice de circularidad y el índice J. Este índice refleja la semejanza de las imágenes de cada semilla con una elipse mostrando diferencias en la forma de las mismas entre accesiones. Los genotipos de J. curcas introducidos en Túnez son polimórficos, su producción de semilla es baja y variable entre genotipos. El análisis morfológico de las semillas da una idea en relación con la producción en algunas de las accesiones. Estudios agronómicos comparativos son cruciales antes de la selección