Consumption of private goods as substitutes for environmental goods in an economic growth model

We analyze growth dynamics in an economy where a private good can be consumed as a substitute for a free access environmental good. In this context we show that environmental deterioration may be an engine of economic growth. To protect themselves against environmental deterioration, economic agents are forced to increase their labour supply to increase the production and consumption of the private good. This, in turn, further depletes the environmental good, leading economic agents to further increase their labour supply and private consumption and so on. This substitution process may give rise to self-enforcing growth dynamics characterized by a lack of correlation between capital accumulation and private consumption levels, on one side, and economic agents’ welfare, on the other. Furthermore, we show that agents’ self-protection consumption choices can generate indeterminacy; that is, they can give rise to the existence of a continuum of (Nash) equilibrium orbits leading to the same attracting fixed point or periodic orbit.Self-protection choices; indeterminacy; undesirable economic growth; negative externalities

Generalized Trust and Sustainable Coexistence between Socially Responsible Firms and Non Profit Organizations

In this paper, we focus on a specific component of economically rel- evant trust, i.e. on what we call `institutionally produced generalized trust', defined as the amount of widespread trust (which is a public good for the economic system as a whole) endogenously and continuously gen- erated by the interaction of two types of private organizations operating in the economy: for-profit firms and nonprofit organizations. Through an evolutionary model with a trust accumulation equation and two replicator equations (capturing the evolution of economic organizations over time) we show that (1) The fixed point where all the four sub-types of private organizations considered in the model are simultaneously present can be attractive only if `virtuous' for-profits (i.e. socially responsible firms) and `virtuous' nonprofits (i.e. actually trustworthy mission-oriented organiza- tions) generate a negative externality on the other organizations of the same type. (2) The fixed point where the level of trust is very low and no socially responsible firms neither trustworthy organizations are present can be attractive; this social configuration interestingly recalls, to some extent, what some prominent social scientists depict as a trend currently occurring in the United States. (3) A socio-economic scenario where four pure population fixed points are simultaneously attractive exists.Generalized trust; socially responsible firms; nonprofit organizations; evolutionary games

Weather Impacts On Natural, Social And Economic System (WISE) Part II: Individual Perception of Climate Extremes in Italy

This paper focuses on the results of the research work carried out by Fondazione Eni Enrico Mattei (FEEM) within the WISE project. This project aims at investigating the effects and the impacts of extreme weather events, particularly very warm summers, mild winters and storms, on the socio-economic systems of European countries. The output consists of a series of empirical studies, both of quantitative and qualitative-descriptive nature. The work of FEEM in the WISE project covers the quantitative analysis of the impacts of climate extremes on the socio-economic system in Italy and the analysis of individuals’ perception of climate extremes based on results from individuals’ surveys. In this paper is considered the study of the perception of weather impacts through questionnaire survey to the general public. With regard to the individuals’ perception survey, a sample of 300 individuals were interviewed by telephone: 150 extracted from the North of Italy and 150 from the South of Italy. Individuals were asked general questions about their perception of climate extremes, and about the impacts of weather extremes on their daily habits at work, at home, in their leisure activities, on their transport patterns, on their health and tourism choices.Climate change, Weather extremes, Perception, Impacts

ENDOGENOUS JOB CONTACT NETWORKS

We develop a model where workers, anticipating the risk of becoming unemployed, invest in connections in order to access information about available jobs that other workers may have. The investment in connections is high when the job separation rate in the labor market is moderate, whereas it is low for either low or high levels of job separation rate. The equilibrium response of network investment to changes in the labor market conditions generates novel empirical predictions. In particular, the probability that a worker finds a new job via his connections increases in the separation rate when the separation rate is low, whereas it decreases when the separation rate is high. These predictions are supported by the empirical patterns that we document for the U.K. labor market

Novel Therapeutic Approach for the Management of Mood Disorders: In Vivo and In Vitro Effect of a Combination of L-Theanine, Melissa officinalis L. and Magnolia officinalis Rehder & E.H. Wilson

Mood disorders represent one of the most prevalent and costly psychiatric diseases worldwide. The current therapies are generally characterized by several well-known side effects which limit their prolonged use. The use of herbal medicine for the management of several psychiatric conditions is becoming more established, as it is considered a safer support to conventional pharmacotherapy. The aim of this study was to investigate the possible anxiolytic and antidepressant activity of a fixed combination of L-theanine, Magnolia officinalis, and Melissa officinalis (TMM) in an attempt to evaluate how the multiple modulations of different physiological systems may contribute to reducing mood disorders. TMM showed an anxiolytic-like and antidepressant-like activity in vivo, which was related to a neuroprotective effect in an in vitro model of excitotoxicity. The effect of TMM was not altered by the presence of flumazenil, thus suggesting a non-benzodiazepine-like mechanism of action. On the contrary, a significant reduction in the effect was observed in animals and neuronal cells co-treated with AM251, a cannabinoid receptor type 1 (CB1) antagonist, suggesting that the endocannabinoid system may be involved in the TMM mechanism of action. In conclusion, TMM may represent a useful and safe candidate for the management of mood disorders with an innovative mechanism of action, particularly as an adjuvant to conventional therapies

Estimating predation impact on honeybees Apis mellifera L. by European bee-eaters Merops apiaster L.

We studied predation pressure on honeybees (Apis mellifera L.) by European bee-eaters (Merops apiaster L.) in five areas with varying bird and insect populations, on the island of Sardinia (Ital y). Number of bee-eater colonies increased with number of food sources (hives and apiaries); conversely total bird population and colony size were not related to food sources. Bee-eaters preyed on bees (foragers) in relation to their mean total availability (calculated over ali study areas), but predation on bees occurred also where hives were absent or far away. By contras!, predation on drones was negatively correlated to their mean total availability. Indeed, predation on foragers and drones correlated negatively. Predation impact on foragers was on average 0.37 % (range: 0.26-0.58 %) of their mean total availability during May-July. The daily forager mortality per hive due to bee-eaterNous avons étudié la pression de prédation sur les abeilles (Apis mellifera L.) par les Guêpiers d'Europe dans cinq zones de l'île de Sardaigne (Italie centrale). Le nombre des colonies d'oiseaux augmentait avec celui des sources de nourriture (ruches et ruchers) ; par contre, ni le nombre total d'oiseaux ni la taille des colonies n'étaient liés au nombre de ruches. Les guêpiers ont prélevé les ouvrières en fonction de leur disponibilité totale moyenne (calculée sur toutes les zones d'étude), mais la prédation sur les abeilles s'est également produite là où les ruches étaient absentes ou très éloignées. En revanche, la prédation sur les faux-bourdons était négativement corrélée avec leur disponibilité totale moyenne. Pourtant, la prédation sur les abeilles était liée négativement à celle sur les faux-bourdons. La pression de prédation sur les ouvrières était en moyenne de 0,37 % (intervalle : 0,26-0,58 %) de leur disponibilité totale moyenne de mai à juillet. La mortalité quotidienne des abeilles par ruche due à la prédation par les guêpiers était en moyenne de 6,1 % (n = 73) de leur mortalité quotidienne totale. La pression de prédation sur les faux-bourdons était en moyenne de 0,91 % (intervalle : 0,27-1,43 %) de leur disponibilité totale moyenne de mai à juillet. La mortalité quotidienne des faux-bourdons par ruche due à la prédation par les guêpiers représentait en moyenne 30 % (n = 4) de leur mortalité quotidienne totale. L'impact de la prédation sur les abeilles était indépendent de la densité de proies, tandis que celui sur les faux-bourdons était négativement lié à la densité des proies et donc dilué aux densités élevées de ruches. L'impact économique sur l'apiculture par les Guêpiers d'Europe est considéré comme négligeable mais les pertes de faux-bourdons ont été localement importantes et potentiellement préjudiciables à des apicultures de petite taille ou spécialisées

Zingiber officinale Roscoe rhizome extract alleviates neuropathic pain by inhibiting neuroinflammation in mice

Background: Current therapies for neuropathic pain are generally symptomatic and possess several side effects, limiting their prolonged usage. Hypothesis/Purpose: Thus, it is urgent to develop novel and safe candidates for the management of this chronical condition. For this purpose, we investigated the analgesic effect of a standardized extract from Zingiber officinale Roscoe rhizomes (ZOE) obtained by CO2 supercritical extraction, in a mice model of peripheral neuropathy. We also explored the mechanism of action of ZOE and its main constituents using an in vitro model of neuroinflammation. Methods: Peripheral mono-neuropathy was induced in mice, by spared nerve injury (SNI). The analgesic effect of ZOE after oral administration was assessed by measuring mechanical and thermal allodynia in SNI mice. The mechanism of action of ZOE and its main constituents were investigated using spinal cords samples and in an in vitro model of neuroinflammation by ELISA, western blotting and immunofluorescence techniques. Results: Oral administration of ZOE 200 mg kg 121 ameliorated mechanical and thermal allodynia in SNI mice, with a rapid and a long-lasting effect. ZOE did not alter locomotor activity. In BV2 cells and spinal cord samples, ZOE, 6-gingerol and 6-shogaol reduced pERK levels, whereas ZOE and terpene fraction reduced HDAC1 protein levels, inhibited NF-\u3baB signalling activation and decreased IL-1\u3b2, TNF-\u3b1 and IL-6 release. ZOE and each tested constituent had a positive effect on inflammation-impaired SH-SY5Y cell viability. Conclusions: The oral administration of ZOE attenuated SNI-induced neuropathic pain symptoms by reducing spinal neuroinflammation, suggesting ZOE as a novel and interesting candidate for the management of neuropathic pain

Global analysis and indeterminacy in a two-sector growth model with human capital

The purpose of the present paper is to highlight some features of global dynamics of the two-sector growth model with accumulation of human and physical capital analyzed by Brito, P. and Venditti, A. (2010). In particular, we explore two cases where the Brito-Venditti system admits two balanced growth paths each of them corresponding, after a change of variables, to an equilibrium point of a 3-dimensional system. In the former one, the two stationary states have, respectively, a 2-dimensional and a 1-dimensional stable manifold (i.e. they are, in the Brito-Venditti terminology, locally indeterminate of order 2 and determinate, respectively). In the latter case, instead, the stable manifolds of the two equilibria have, respectively, dimension two and three (i.e. they are locally indeterminate of order 2 and 3). In both cases we prove the possible existence of points P such that in any neighborhood of P lying on the plane corresponding to a fixed value of the state variable there exist points Q whose positive trajectories tend to either equilibrium point. Moreover we show examples where the 2-dimensional stable manifold of the order 2 locally indeterminate equilibrium, in the former case, and the basin of the attracting equilibrium, in the latter case, are proven to be both unbounded

Global analysis and indeterminacy in a two-sector growth model with human capital

The purpose of the present paper is to highlight some features of global dynamics of the two-sector growth model with accumulation of human and physical capital analyzed by Brito, P. and Venditti, A. (2010). In particular, we explore two cases where the Brito-Venditti system admits two balanced growth paths each of them corresponding, after a change of variables, to an equilibrium point of a 3-dimensional system. In the former one, the two stationary states have, respectively, a 2-dimensional and a 1-dimensional stable manifold (i.e. they are, in the Brito-Venditti terminology, locally indeterminate of order 2 and determinate, respectively). In the latter case, instead, the stable manifolds of the two equilibria have, respectively, dimension two and three (i.e. they are locally indeterminate of order 2 and 3). In both cases we prove the possible existence of points P such that in any neighborhood of P lying on the plane corresponding to a fixed value of the state variable there exist points Q whose positive trajectories tend to either equilibrium point. Moreover we show examples where the 2-dimensional stable manifold of the order 2 locally indeterminate equilibrium, in the former case, and the basin of the attracting equilibrium, in the latter case, are proven to be both unbounded