On Negative Time Preference

Survey data show that subjects positively discount both gains and losses but discount gains more heavily than losses. This holds for monetary and non-monetary outcomes

An experiment on experimental instructions

In this paper we treat instructions as an experimental variable. Using a public good game, we study how the instructions' format affects the participants' understanding of the experiment, their speed of play and their experimental behavior. We show that longer instructions do not significantly improve the subjects' understanding of the experiment; on-screen instructions shorten average decision times with respect to on-paper instructions, and requiring forced inputs reduces waiting times, in particular for the slowest subjects. Consistent with cognitive load theory, we find that short, on-screen instructions which require forced inputs improve on subjects' comprehension and familiarity with the experimental task, and they contribute to reduce both decision and waiting times without affecting the overall pattern of contributions.

La siccità e la disponibilità di acque sotterranee in Puglia

Mediante l'utilizzo di metodi di statistica delle serie storiche è stato possibile evidenziare alcuni caratteri degli acquiferi pugliesi, quali il regime piezometrico, i rapporti intercorrenti tra precipitazioni meteoriche, temperatura atmosferica e variazioni piezometriche. La ricostruzione degli aspetti tendenziali, negli ultimi 30 anni, delle variazioni piezometriche ha mostrato un abbassamento considerevole della quota piezometrica in tutte le unità idrogeologiche, con valori più accentuati per le aree interne della Murgia e del Tavoliere. Gli elementi raccolti segnalano un progressivo depauperamento delle falde idriche proprio dove si concentrano le acque sotterranee di migliore qualità. Si rende necessaria, quindi, una politica gestionale delle risorse idrica sotterranee che consenta agli acquiferi di accumulare acque sotterranee nei periodi umidi, in cui abbondano le acque di superficie, per restituirle nei periodi aridi, svolgendo una funzione di compenso pluriennale

Gli effetti antropici e climatici sulla disponibilità delle acque sotterranee della Piana ionico-lucana

The paper deals with the groundwater availability along the lonian coastal plain (Southern Italy), between the mouths of Sinni and Bradano Rivers. Subjected to intense agricultural and tourism activities, the availability of the tapped groundwater is seriously important for the economic growth ofthis coastal area, especially due to the increasing frequency of droughts. The stratigraphical and hydrogeological set-up of the area as the geochemical features of the groundwater arise from the data analysis of 1130 boreholes, widespread over the whole area and from 1.3 up to 423 meters deep. The aquifers of the area could be distinguished in two types. The former encloses aquifers constituted by marine terraced deposits and alluvial river valleys deposits. The latter includes that one of the coastal plain deposits. It is the most interesting for practical utilisation and it is considered in the paper. The analysis of long time series is based on piezometric data (1927 to 1984), monitored by 60 wells, temperature, rainfall and river discharge data. The piezometric regimen and the maximum piezometric variation are characterised. The trend analysis, the autocorrelation and the crosscorrelation were applied to all variables. As a result, the modification of groundwater availability was characterised considering the spatial variation of the hydrogeological conditions. The relationships existing between rainfall, temperature, river discharge variations and piezometric surface height

The role of climate in promoting landslides in the seismic area of the Appennines, Southern Italy

The study area is located in Southern Italy, southeast of Naples (Figure 1). The phenomena of slope instability and floods have long been a constant feature in this portion of the Apennines, with earthquakes and meteoric events accounting for the main triggering factors. Landslides have often resulted in dreadful economic and human losses. A magnitude-6.8 earthquake that triggered many large landslides hit the study area on November 23, 1980. A number of geological, geomorphological, hydrological and geotechnical features of the study area are examined in detail in the final technical report of an EEC research project (EEC 1996). This paper examines the space distribution of rainfall and temperature accounting for the distribution of landslides before the earthquake on 23 November 1980 and the changes occurred afterwards. The major climatic elements, namely monthly precipitation and temperature, are analysed with geostatistic methods and discussed. The space variability is compared to the landslide proneness distribution within the area

Trend termopluviometrico, siccità e disponibilità di acque sotterranee in Italia meridionale

Si caratterizzano le tendenze delle variabili climatiche che determinano la disponibilità di risorse idriche e gli effetti sulla disponibilità di acque sotterranee, analizzando serie temporali mensili inerenti piovosità e temperatura di 126 stazioni collocate in Italia meridionale, tra il 1821 e il 2005. È emersa una tendenza al calo pluviometrico che riguarda il 95% dell’area, dovuto in particolare ad un consistente deficit di precipitazioni a partire dal 1980. La tendenza negativa è accentuata in inverno, solitamente stagione più piovosa su gran parte dell’area considerata. Questo fattore, congiuntamente con temperature maggiori della media ossservate con regolarità dal 1980, determina per la piovosità efficace una tendenza al calo ancora più grave. Gli effetti sulle acque sotterranee sono stati valutati mediante serie storiche mensili considerando vasti acquiferi in Basilicata, Calabria e Puglia, caso descritto nel dettaglio. Ovunque si osserva una spiccata tendenza al calo piezometrico

Effetti antropici e naturali sul degrado quantitativo delle acque sotterranee del Tavoliere

This work is based on data acquisition and analysis of chronology sequences of piezometric, rainfall, thermometric and runoff data of Apulian Tableland aquifer. Methods of time series analysis are used. This approach has allowed characterising the piezometric regime and trend related to the natural recharge variation. The historical character of measurement period, last sixty years, is very important to evaluate the human effect