Delegation with a Reciprocal Agent

We consider a model in which a principal may delegate the choice of a project to a better informed agent. The preferences of the agent and the principal about which project should be undertaken may be discordant. Moreover, the agent benefits from being granted more discretion in the project choice and may be motivated by reciprocity. We find that the relationship between the agent's reciprocity and discretion crucially depends on the conflict of interest with the principal. When preferences are more congruent (discordant), discretion is broader (more limited) if the agent is more reciprocal. Hence, reciprocity mitigates (exacerbates) a mild (severe) conflict of interest. We also present supportive evidence for the predictions of our model using the German Socio-Economic Panel dataset

Energy constrained sandpile models

We study two driven dynamical systems with conserved energy. The two automata contain the basic dynamical rules of the Bak, Tang and Wiesenfeld sandpile model. In addition a global constraint on the energy contained in the lattice is imposed. In the limit of an infinitely slow driving of the system, the conserved energy $E$ becomes the only parameter governing the dynamical behavior of the system. Both models show scale free behavior at a critical value $E_c$ of the fixed energy. The scaling with respect to the relevant scaling field points out that the developing of critical correlations is in a different universality class than self-organized critical sandpiles. Despite this difference, the activity (avalanche) probability distributions appear to coincide with the one of the standard self-organized critical sandpile.Comment: 4 pages including 3 figure

Concept, prototyping and application of a tensioning system for FRP ties into masonry structures

The present paper deals with concept, prototyping and application of a tensioning system for FRP ties into masonry structures. The proposed system, based on the use of FRP strands instead of traditional steel ties, has the aim to produce a compression stress state on masonry walls where it is applied. Given the objective difficulty in tensioning a FRP strand, it has been necessary to both characterize and prototype a suitable connection system between the strand and the pulling system. The experimental phase concerned both the manufacturing of the pulling system and the study of used materials, as well as the characterization of the impregnation technology of FRP ties. The above described system has been produced and used in the framework of the structural retrofitting of the “Real Albergo dei Poveri” building in Naples

Mean-field behavior of the sandpile model below the upper critical dimension

We present results of large scale numerical simulations of the Bak, Tang and Wiesenfeld sandpile model. We analyze the critical behavior of the model in Euclidean dimensions $2\leq d\leq 6$. We consider a dissipative generalization of the model and study the avalanche size and duration distributions for different values of the lattice size and dissipation. We find that the scaling exponents in $d=4$ significantly differ from mean-field predictions, thus suggesting an upper critical dimension $d_c\geq 5$. Using the relations among the dissipation rate $\epsilon$ and the finite lattice size $L$, we find that a subset of the exponents displays mean-field values below the upper critical dimensions. This behavior is explained in terms of conservation laws.Comment: 4 RevTex pages, 2 eps figures embedde

Corruption and the regulation of innovation

We study the optimal design of regulation for innovative activities which can have negative social repercussions. We compare two alternative regimes which may provide firms with different incentives to innovate and produce: lenient authorization and strict authorization. We find that corruption plays a critical role in the choice of the authorization regime. Corruption exacerbates the costs of using lenient authorization, under which production of socially harmful goods is always authorized. In contrast, corruption can be socially beneficial under strict authorization, since it can mitigate an over-investment problem. In the second part of the paper, we explore the design of bonuses, taxes, and ex-post liability to improve the regulatory outcome

inheritance of suri and huacaya type of fleece in alpaca

The inheritance of the two types of fleece, Suri and Huacaya, observed in Alpaca (Lama pacos L.) is still not clearly defined. The objective of this work is to investigate the patter of inheritance of these two phenotypes, throughout 588 Suri x Suri and 2126 Huacaya x Huacaya offspring. The single gene and the three two-phenotype epistatic models were tested in the 19 Suri x Suri segregating families. The single dominant gene hypothesis best fitted our segregation data and could be, therefore, accepted (GT=20.276, P=0.378). The gene frequency of the recessive Huacaya allele was 0.295, being the frequency of the dominant Suri allele 0.705. The frequency of heterozygotes, estimated in the whole population and among dominant individuals, was 0.416 and 0.455, respectively, with a "carrier" Suri to Huacaya ratio of 4.780. In three Huacaya families, 3 Suri were born, as a result of a new dominant mutation on some germinal lines of Huacaya animals. The direct mutation rate can be estimated at 0.0014

Delegation with a Reciprocal Agent [WP]

We consider a model in which a principal may delegate the choice of a project to a better informed agent. The preferences of the agent and the principal about which project should be undertaken can be discordant. Moreover, the agent benefits from being granted more discretion in the project choice and may be motivated by reciprocity. We find that the impact of the agent's reciprocity on the discretion he receives crucially depends on the conflict of interest with the principal. If preferences are very discordant, the principal is more likely to retain authority about the choice of the project when the agent is more reciprocal. Hence, reciprocity exacerbates a severe conflict of interest. In contrast, if preferences are more congruent, discretion is broader when the agent is more reciprocal. Hence, reciprocity mitigates a mild conflict of interest. In addition, we find that the possibility of being able to offer monetary payments to the agent can make the principal worse off when the agent reciprocates. We also empirically test the predictions of our model using the German Socio-Economic Panel finding some support for our theoretical results