5 resultados para Threshold choice
em AMS Tesi di Dottorato - Alm@DL - Università di Bologna
Resumo:
People are daily faced with intertemporal choice, i.e., choices differing in the timing of their consequences, frequently preferring smaller-sooner rewards over larger-delayed ones, reflecting temporal discounting of the value of future outcomes. This dissertation addresses two main goals. New evidence about the neural bases of intertemporal choice is provided. Following the disruption of either the medial orbitofrontal cortex or the insula, the willingness to wait for larger-delayed outcomes is affected in odd directions, suggesting the causal involvement of these areas in regulating the value computation of rewards available with different timings. These findings were also supported by a reported imaging study. Moreover, this dissertation provides new evidence about how temporal discounting can be modulated at a behavioral level through different manipulations, e.g., allowing individuals to think about the distant time, pairing rewards with aversive events, or changing their perceived spatial position. A relationship between intertemporal choice, moral judgements and aging is also discussed. All these findings link together to support a unitary neural model of temporal discounting according to which signals coming from several cortical (i.e., medial orbitofrontal cortex, insula) and subcortical regions (i.e., amygdala, ventral striatum) are integrated to represent the subjective value of both earlier and later rewards, under the top-down regulation of dorsolateral prefrontal cortex. The present findings also support the idea that the process of outcome evaluation is strictly related to the ability to pre-experience and envision future events through self-projection, the anticipation of visceral feelings associated with receiving rewards, and the psychological distance from rewards. Furthermore, taking into account the emotions and the state of arousal at the time of decision seems necessary to understand impulsivity associated with preferring smaller-sooner goods in place of larger-later goods.
Resumo:
This dissertation is about collective action issues in common property resources. Its focus is the “threshold hypothesis,” which posits the existence of a threshold in group size that drives the process of institutional change. This hypothesis is tested using a six-century dataset concerning the management of the commons by hundreds of communities in the Italian Alps. The analysis seeks to determine the group size threshold and the institutional changes that occur when groups cross this threshold. There are five main findings. First, the number of individuals in villages remained stable for six centuries, despite the population in the region tripling in the same period. Second, the longitudinal analysis of face-to-face assemblies and community size led to the empirical identification of a threshold size that triggered the transition from informal to more formal regimes to manage common property resources. Third, when groups increased in size, gradual organizational changes took place: large groups split into independent subgroups or structured interactions into multiple layers while maintaining a single formal organization. Fourth, resource heterogeneity seemed to have had no significant impact on various institutional characteristics. Fifth, social heterogeneity showed statistically significant impacts, especially on institutional complexity, consensus, and the relative importance of governance rules versus resource management rules. Overall, the empirical evidence from this research supports the “threshold hypothesis.” These findings shed light on the rationale of institutional change in common property regimes, and clarify the mechanisms of collective action in traditional societies. Further research may generalize these conclusions to other domains of collective action and to present-day applications.
Resumo:
Concerns of Thai consumers on food safety have been recently increasing, especially in urban areas and for fresh produce because food safety scandals, such as chemical residues on fresh produce (e.g., cabbage) still frequently occur. The Thai government tried to meet consumer needs by imposing in the domestic market a stronger regulation aimed at increasing the baseline level of food safety assurance and by introducing a voluntary standard (based on Good Agricultural Practices or GAPs and known as Q-GAP) and the related food safety label (i.e., Q mark). However, since standards and regulations are weakly implemented in the domestic market compared to exported products, there is still a lack of Thai consumers’ confidence in the safety of local food products. In this work the current situation of GAPs adoption in Thai fresh produce production is analysed. Furthermore, it is studied whether Thai consumers place value on food safety labels available on the market, to know whether consumer demand could drive the market of certified safer products. This study contains three essays: 1) a review of the literature, 2) a qualitative study on stakeholders' perception toward GAPs adoption and 3) a quantitative study, aimed at analysing consumers' preferences and willingness-to-pay for food safety labels on fresh produce using a discrete choice experiment. This dissertation contributes to the economics of quality assurance and labelling, specifically addressing GAPs and food safety label in the fresh produce supply chain. Results show that Q-GAP could be effectively used to improve food safety in Thai domestic market, but its credibility should be improved. Stakeholder’s awareness toward food safety issues and the delivery of reliable and sound information are crucial. Thai consumers are willing to pay a premium price for food safety labelled produce over unlabelled ones. Implications for both government and business decision-makers are discussed.
Resumo:
Depending on the regulatory regime they are subject to, governments may or may not be allowed to hand out state aid to private firms. The economic justification for state aid can address several issues present in the competition for capital and the competition for transfers from the state. First, there are principal-agent problems involved at several stages. Self-interested politicians might enter state aid deals that are the result of extensive rent-seeking activities of organized interest groups. Thus the institutional design of political systems will have an effect on the propensity of a jurisdiction to award state aid. Secondly, fierce competition for firm locations can lead to over-spending. This effect is stronger if the politicians do not take into account the entirety of the costs created by their participation in the firm location race. Thirdly, state aid deals can be incomplete and not in the interest of the citizens. This applies if there are no sanctions if firms do not meet their obligations from receiving aid, such as creating a certain number of jobs or not relocating again for a certain amount of time. The separation of ownership and control in modern corporations leads to principal-agent problems on the side of the aid recipient as well. Managers might receive personal benefits from subsidies, the use of which is sometimes less monitored than private finance. This can eventually be to the detriment of the shareholders. Overall, it can be concluded that state aid control should also serve the purpose of regulating the contracting between governments and firms. An extended mandate for supervision by the European Commission could include requirements to disincentive the misuse of state aid. The Commission should also focus on the corporate governance regime in place in the jurisdiction that awards the aid as well as in the recipient firm.
Resumo:
In questa tesi dottorale viene preso in analisi il tema della famiglia, uno degli elementi fondanti della riflessione pedagogica, crocevia di una molteplicità di nuclei interpretativi con diramazioni e contaminazioni, con mutamenti attraverso le epoche storiche, rappresentati in pagine contenute nei Classici della letteratura per l’infanzia e nei migliori libri di narrativa contemporanea. Si tratta di un tema di grande ampiezza che ha comportato una scelta mirata di Autori che, nei loro romanzi hanno trattato questioni riguardanti la famiglia nelle sue pluralità delle sue tante accezioni, dalla vita familiare agli abbandoni, dalle infanzie senza famiglia alle famiglie altre. Nelle diverse epoche storiche, le loro narrazioni hanno lasciato un segno per l'originalità interpretativa che ancora oggi ci raccontano storie di vie familiale Dai romanzi ottocenteschi alle saghe fantasy degli ultimi cinquant’anni, fino ai picturebook, destinati ai più piccoli, le families stories possono costituire un materiale pedagogico privilegiato, sia offrendo occasioni di scoperta e conoscenza di sé e del mondo, attraverso le quali i lettori bambini, enigmatici frontalieri, varcano soglie verso altrovi misteriosi, sia fornendo spunti agli studiosi per approfondire tematiche multiple e complesse. Le families stories riflettono spesso in maniera critica le divergenze che possono manifestarsi tra le prassi individuate e studiate dalle scienze umane e sociali e le metafore narrative proposte dai numerosi Autori della letteratura per l’infanzia. Proponendo una prospettiva spesso spiazzante, esse interpretano la realtà a fondo, cogliendo i più piccoli ed inosservati particolari che, invece, hanno la capacità di rompere gli schemi socio-educativi dell’epoca storica in cui le storie prendono vita.