Revisiting the comovement puzzle: the input-output structure as an additional solution

We propose an additional solution to the comovement puzzle by developing a two-sector monetary model with housing production and an input-output structure. The model generates comovement between consumption and residential investment for large range of shocks hitting the economy. Consistent with previous work, we find that our model produces highly persistence responses in aggregate consumption, aggregate output and residential investment. We show that the results are highly robust to different policy rule specifications. We find that the lower the labour shares, the higher the relative volatility of residential investment. The model with an IO structure is works under different specifications of the period utility function. We extend the model to allow for wage rigidities and show that our proposed solution can perfectly work alongside previous ones

The 4.2 ka event in the vegetation record of the central Mediterranean

In this paper, the variation in forest cover in the central Mediterranean region, reflected by percentage changes in the arboreal pollen record, has been examined in relation to the 4.2 ka event. A total of 36 well-dated and detailed pollen records from latitudes between 45 and 36 degrees N were selected and their vegetation dynamics between 5 and 3 ka examined in relation to the physiographic and climatic features of the study area and to the influence of human activity on past vegetation, as suggested by anthropogenic pollen indicators. We have found that the sites located between 43 and 45 degrees N do not show any significant vegetation change in correspondence with the 4.2 ka event. Several sites located on the Italian Peninsula between 39 and 43 degrees N show a marked opening of the forest, suggesting a vegetation response to the climate instability of the 4.2 ka event. Between 36 and 39 degrees N, a forest decline is always visible around 4.2 ka, and in some cases it is dramatic. This indicates that this region was severely affected by a climate change towards arid conditions that lasted a few hundred years and was followed by a recovery of forest vegetation in the Middle Bronze Age. Human activity, especially intense in southern Italy, may have been favored by this natural opening of vegetation. In Sardinia and Corsica, no clear change in vegetation is observed at the same time. We suggest that during the 4.2 ka event southern Italy and Tunisia were under the prevalent influence of a north African climate system characterized by a persistent high-pressure cell

A Note on Wealth as a Corruption-Controlling Device

In the standard moral hazard model, withholding of effort by the agent is not observable to the principal. We argue that this assumption has to be changed in applications that study corruption. The overwhelming majority of cases where corrupt politicians have been punished involve the detection of consumption levels that appear to be too high. The informativeness of an agent’s level of consumption depends on his initial level of wealth as conspicuous consumption of luxuries by wealthy agents leads to little updating of the principal’s belief about their honesty. This introduces a tendency to choose poor agents as they are easier to monitor. More generally, we show that, even if agents have similar preferences, there are contractual advantages to selecting particular types. We describe the basic problem of choosing agents and monitoring consumption, and discuss a number of features of the practical applications. We show that selecting rich politicians may not help fight corruption and that the political class will exhibit lower variance in consumption than the population. In settings were formal contracts matter, we show that monitoring consumption introduces a tendency towards low powered incentive schemes (and more generally low wages) and that the measure of “moral” costs that is often employed in the literature can be derived (not assumed).Choosing agents, monitoring consumption, low wages, moral costs

The evolution of world trade and the Italian ‘anomaly': a new look

This work provides an empirical assessment of the 'sophistication' of the Italian international specialization pattern and of its evolution during the period 1980 � 2000. In particular we analyse the well-known Italian trade 'anomaly' combining the information coming from the PRODY index (Hausmann et al. (2005)) with the RCA index. Our results show that in the last two decades, the world trade has been rapidly changing with Italy becoming increasingly more competitive and specialized in products that are characterized by decreasing income/productivity levels. Thus, while the Italian 'anomaly' was not a problem in the past, it may have become an obstacle to future growth.PRODY index,RCA,Specialization pattern

Choosing Agents and Monitoring Consumption: A Note on Wealth as a Corruption-Controlling Device

There are a large number of cases where corruption has been discovered investigating levels of consumption that appear to be hard to justify. Yet, in the standard moral hazard model withholding of effort by the agent is not observable to the principal. We argue that this assumption has to be revised in applications that study corruption. The informativeness of an agent's level of consumption depends on his legal income and initial level of wealth, as conspicuous consumption by wealthy agents leads to little updating of the principal's belief about their honesty. This introduces a tendency to prefer poor agents as they are easier to monitor. More generally, we describe the basic problem of choosing agents and monitoring consumption with the aim of reducing corruption, and discuss features of the practical applications. We show that when there is consumption monitoring and wealth is observed, the effect of higher wealth on equilibrium bribes is ambiguous (and that the political class will exhibit lower variance in consumption than the general population). In settings where formal contracts matter, we show that monitoring consumption introduces a tendency towards low powered incentives (and more generally low wages). We also discuss the role of ability, the tax system, and the way to derive a measure of the value of illegal funds for the agent.

The Evolution of the World Trade and the Italian ‘Anomaly’: A New Look

This work provides an empirical assessment of the âsophisticationâ of the Italian international specialization pattern and of its evolution during the period 1980−2000. In particular we discuss the Italian âanomalyâ, i.e. the evidence that Italy displays a specialization pattern more similar to the one of emerging economies than to the one of countries of comparable level of per-capita income. We show that combining the information coming from a new index measuring the income/productivity content of traded goods, i.e. the PRODY index recently proposed in Hausmann et al. (2005), with the index of Revealed Comparative Advantages (RCA) can shed light on the Italian anomaly. We begin providing a detailed picture of the theoretical and empirical characteristics of the PRODY index. In particular we calculate the index for 1980, 1990 and 2000 mapping its dynamics through that period. Then we describe the characteristic and evolution of the Italian RCA using both parametric and non parametric techniques finding that the Italian pattern of specialization is particularly persistent. Finally, we describe the co-evolution of the PRODY and of the RCA indexes. Our analysis shows that in the last two decades, the world trade has been rapidly changing with Italy becoming increasingly more competitive and specialized in products that are characterized by decreasing income/productivity levels. Thus, while the Italian âanomalyâ was not a problem in the past, it may have become an obstacle to future growth.Specialization pattern, RCA, PRODY index, Italian ’anomaly’

Collapse or transformation? Regeneration and innovation at the turn of the first millennium BC at Arslantepe, Turkey

Ongoing excavations at Arslantepe in south-eastern Turkey are revealing settlement continuity spanning two crucial phases at the transition from the second to the first millennium BC: the post-Hittite period and the development of Syro-Anatolian societies

Robust multi-clue face tracking system

In this paper we present a multi-clue face tracking system, based on the combination of a face detector and two independent trackers. The detector, a variant of the Viola-Jones algorithm, is set to generate very low false positive error rate. It initiates the tracking system and updates its state. The trackers, based on 3DRS and optical flow respectively, have been chosen to complement each other in different conditions. The main focus of this work is the integration of the two trackers and the design of a closed loop detector-tracker system, aiming at achieving superior robustness at real-time operation on a PC platform. Tests were carried out to assess the actual performance of the system. With an average of about 95% correct face location rate and no significant false positives, the proposed approach appears to be particularly robust to complex backgrounds, ambient light variation, face orientation and scale changes, partial occlusions, different\ud facial expressions and presence of other unwanted faces

U(1)U(1) flavour symmetries as Peccei-Quinn symmetries

We investigate to what extent a generic, generation-dependent $U(1)$ symmetry acting on the quark Yukawa operators can reduce the number of free parameters by forcing some entries in the Yukawa matrices to vanish. The maximal reduction compatible with CP violation yields nine real parameters and one phase, which matches the number of physical observables, implying that such models have no free parameters. We derive a set of results: (i) the only possible structures have the form $M_4 \oplus M_5$, where the subscripts indicate the number of real parameters in the Yukawa matrices, (ii) there are only two inequivalent Yukawa structures, each one giving rise to six different models depending on quark flavour assignments, (iii) the $U(1)$ symmetries that generate these textures all have a QCD anomaly, and hence are Peccei-Quinn symmetries, reinforcing the idea of a possible connection between the quark flavour puzzle and the axion solution to the strong CP problem, (iv) in some cases the contributions to the QCD anomaly of two generations cancels out, and this opens the possibility that the axion coupling to nucleons could be strongly suppressed. Flavour-violating axion couplings to quarks are completely fixed, up to the axion decay constant, providing a non-trivial complementarity between low-energy flavour-violating processes and standard axion searches.Comment: v2: version accepted for publication in JHEP; figure 1 updated; minor additions; 23 pages, 1 figure. v1: 20 pages, 1 figur

A Software Suite for the Control and the Monitoring of Adaptive Robotic Ecologies

Adaptive robotic ecologies are networks of heterogeneous robotic devices (sensors, actuators, automated appliances) pervasively embedded in everyday environments, where they learn to cooperate towards the achievement of complex tasks. While their flexibility makes them an increasingly popular way to improve a system’s reliability, scalability, robustness and autonomy, their effective realisation demands integrated control and software solutions for the specification, integration and management of their highly heterogeneous and computational constrained components. In this extended abstract we briefly illustrate the characteristic requirements dictated by robotic ecologies, discuss our experience in developing adaptive robotic ecologies, and provide an overview of the specific solutions developed as part of the EU FP7 RUBICON Project