Measuring social capital: culture as an explanation of Italy’s economic dualism

The paper presents a quantitative test of the oft-repeated view that Italy’s backward and poor South suffered from low “social capital”, a tendency to defect from co-operative engagements. The problem with such assertions is that they run the risk of taking as evidence in favour of the hypothesis the very observations that need to be explained. The analysis carried out in this work tries to break out of this impasse by analysing the conditions under which it was ex ante welfare-improving for farmers in early 20th century Italy to join an unlimited liability rural co-operative bank which would give them access to cheaper credit but also exposed them to the risk of their neighbours’ defection. These co-ops are a prime testing ground for the cultural explanation in that they spread rapidly throughout Northern Italy in the late 19th century, but never gained a similar popularity in the South. I estimate the switching function for these co-ops in different parts of the country to test whether Northern and Southern farmers faced significantly different choice sets when making the decision to join. Identical choice sets but differential responses would of course favour the cultural explanation of the South’s backwardness. The results suggest that for the same parameter values, the choice sets for North and South were different, though whether this difference was large enough to explain the full difference in responses is not completely clear

Strong spectral evolution during the prompt emission of GRB 070616

Swift has revealed features in GRB early light curves, such as steep decays and X-ray flares, whose properties are consistent with an internal origin though they are far from understood. The steep X-ray decay is often explained using the curvature effect; however a significant number of GRBs display strong spectral evolution during this phase, and a new mechanism must be invoked to explain this. Of particular interest are the longest duration GRBs in which the early emission can be studied in most detail. Here we present data for GRB 070616, in which the prompt emission shows a complex multipeaked structure, leading to one of the longest prompt emission durations ever recorded. We take advantage of extensive coverage of such a long burst by all Swift instruments. Combining data from Swift and Suzaku we study the evolution of the prompt emission spectrum, following the temporal variability of the peak energy and spectral slope.Comment: 4 pages, 2 figures (Fig 1 in colour), contributed talk, submitted to the proceedings of Gamma Ray Bursts 2007, Santa Fe, New Mexico, November 5-9 200

From drought to flood: environmental constraints and the political economy of civic virtue

The paper models co-operative engagement under varying environmental constraints giving rise to different forms of collective action problems, specifically focussing on water management in pre-industrial societies. I show that societies where water availability is strongly seasonal develop no mechanism to encourage society-wide co-operative behaviour because the benefits of water storage are fully excludable. With pre-industrial technology water storage is a pure club good, and optimal club size can be shown to be very small under credible parameter values, converging to 1 in some cases (private good). The social consequences of the environmental constraint include strongly circumscribed co-operation and rent seeking. In contrast, areas where water management involved flood control and irrigation develop society-wide institutions based on self-sustaining co-operative engagement assisted by external policing. The model thus offers an explanation of varying levels of "civic virtue" in different areas

My word is my bond: reputation as collateral in nineteenth century English provincial banking

There are few real-world economic transactions that do not involve an element of trust, yet in textbook economics trust is not prominently discussed. In that world, perfectly informed and computationally endowed agents reach optimal, enforceable decisions in continuously harmonising exchanges. Trust is therefore linked to deviations from the textbook ideal: incomplete information, costly enforcement, and computational limitations faced by agents. Trust can then be thought of as an algorithm, in other words, a way of resolving uncertainty in a complex world. In this sense trust may be seen as a form of expectation concerning the behaviour of other agents whose actions and intentions cannot be (fully) observed. This paper pursues this approach by “running the algorithm backwards” and trying to establish what factors led a 19th century provincial English bank to trust different loan applicants. Using a data-set of some 200 loan decisions, and knowing the size of collateral (if any) requested, we develop a method to estimate the probability that the bank attached to each borrower’s promise to repay (i.e., the trust the bank had towards the borrower), adjusting for stages in the business cycle. We then regress this estimated probability on a variety of observable borrower characteristics. We find that trust is not correlated with a priori expected variables, such as borrower’s assets or frequency of interaction. This suggests that trust was built up in other interactions, possibly through social or religious networks, and that the banking relationship reflected information available to bank directors other than what was purely pertinent to the borrowers’ economic conditions. This has strong implications for the allocation of credit to industry in 19th century England

Output risk in Tuscan agriculture in the late 19th and early 20th centuries

We analyse output risk in Italian agriculture over the period 1870-1914. We use data on a set of 16 tenanted plots grouped into three farms comprising a single large estate. We estimate the degree of risk associated with each separate crop, with the portfolio of crops at the level of the plot, the farm and the estate. We highlight two particular features: the relatively high risk associated with tree crops (wine, oil and nuts); and the substantial scope for the landlord to reduce risk through crop diversification across plots. We discuss the implications of these for tenure contract theory

Coherent Control of Trapped Bosons

We investigate the quantum behavior of a mesoscopic two-boson system produced by number-squeezing ultracold gases of alkali metal atoms. The quantum Poincare maps of the wavefunctions are affected by chaos in those regions of the phase space where the classical dynamics produces features that are comparable to hbar. We also investigate the possibility for quantum control in the dynamics of excitations in these systems. Controlled excitations are mediated by pulsed signals that cause Stimulated Raman Adiabatic passage (STIRAP) from the ground state to a state of higher energy. The dynamics of this transition is affected by chaos caused by the pulses in certain regions of the phase space. A transition to chaos can thus provide a method of controlling STIRAP.Comment: 17 figures, Appended a paragraph on section 1 and explained details behind the hamiltonian on section

Functional biases in GRB's spectral parameter correlations

Gamma Ray Bursts (GRBs) show evidence of different spectral shapes, light curves, duration, host galaxies and they explode within a wide redshift range. However, the most of them seems to follow very tight correlations among some observed quantities relating to their energetic. If true, these correlations have significant implications on burst physics, giving constraints on theoretical models. Moreover, several suggestions have been made to use these correlations in order to calibrate GRBs as standard candles and to constrain the cosmological parameters. We investigate the cosmological relation between low energy $\alpha$ index in GRBs prompt spectra and the redshift $z$. We present a statistical analysis of the relation between the total isotropic energy $E_{iso}$ and the peak energy $E_p$ (also known as Amati relation) in GRBs spectra searching for possible functional biases. Possible implications on the $E_{iso}$ vs $E_p$ relation of the $\alpha$ vs $(1+z)$ correlation are evaluated. We used MonteCarlo simulations and the boostrap method to evaluate how large are the effects of functional biases on the $E_{iso}$ vs $E_p$. We show that high values of the linear correlation coefficent, up to about 0.8, in the $E_{iso}$ vs $E_p$ relation are obtained for random generated samples of GRBs, confirming the relevance of functional biases. Astrophysical consequences from $E_{iso}$ vs $E_p$ relation are then to be revised after a more accurate and possibly bias free analysis.Comment: 6 pages, 6 figures, conference poster session: "070228: The Next Decade of Gamma-Ray Burst Afterglows", Amsterdam, March 2007, MNRAS submitte

Switchable Genetic Oscillator Operating in Quasi-Stable Mode

Ring topologies of repressing genes have qualitatively different long-term dynamics if the number of genes is odd (they oscillate) or even (they exhibit bistability). However, these attractors may not fully explain the observed behavior in transient and stochastic environments such as the cell. We show here that even repressilators possess quasi-stable, travelling-wave periodic solutions that are reachable, long-lived and robust to parameter changes. These solutions underlie the sustained oscillations observed in even rings in the stochastic regime, even if these circuits are expected to behave as switches. The existence of such solutions can also be exploited for control purposes: operation of the system around the quasi-stable orbit allows us to turn on and off the oscillations reliably and on demand. We illustrate these ideas with a simple protocol based on optical interference that can induce oscillations robustly both in the stochastic and deterministic regimes.Comment: 24 pages, 5 main figure

Effect of beet pulp on growing performance, digestibility, N balance, and ammonia emission in the heavy pig

A relevant aspect of pig farm units concerning the environmental impact is the ammonia emission from slurries, which is detrimental for animal (and sometimes also for human) welfare. This emission is co-responsible for acid rains, for the increase of bad smells and is detrimental for the respiratory apparatus (Portejoie et al., 2002)

GRBs and the thermalization process of electron-positron plasmas

We discuss the temporal evolution of the pair plasma created in Gamma-Ray Burst sources. A particular attention is paid to the relaxation of the plasma into thermal equilibrium. We also discuss the connection between the dynamics of expansion and the spatial geometry of the plasma. The role of the baryonic loading parameter is emphasized.Comment: 4 pages, 3 figures, in the Proceedings of the "Gamma Ray Bursts 2007" meeting, November 5-9, 2007, Santa Fe, New Mexico, US