Institutions, Famine and Inequality

In this paper we analyze whether and which political institutions are important for famine prevention and for keeping the levels of inequality low. While famines are sudden crises hitting a country, inequality is a structural problem. As a consequence, the institutions needed might be very different. The econometric exercises realized on a group of emerging and developing countries confirm the validity of Amartya Sen’s “democracy prevents famine” argument, while democracy is not a significant determinant of income inequality. These results are in line with previous ones, suggesting an unclear role of democratic institutions in facing other structural problems, such as hunger and poverty. Moreover, two main institutional indicators, computed by the World Bank, “control of corruption” and “government effectiveness” are negatively correlated with famine mortality, suggesting that the policy environment, the level of bureaucracy, governmental capacity to take decisions and implement them in a short period are relevant factors for reducing famine mortality. In contrast, political stability explains better income inequality in our sample of countries. Social peace and cohesion are deterrent for inequality, but the direction of the relationship should be investigated further.Famine; Inequality; Institutions; Democracy; Cross-country analysis

Sales and Collusion in a Market with Storage

Sales are a widespread and well-known phenomenon that has been documented in several product markets. Regularities in such periodic price reductions appear to suggest that the phenomenon cannot be entirely attributed to random variations in supply, demand, or the aggregate price level. Certain sales are traditional and so well publicized that it is difficult to justify them as devices to separate informed from uninformed consumers. This paper presents a model in which sellers want to reduce prices periodically in order to improve their ability to collude over time. In particular, the study shows that if buyers have heterogeneous storage technologies, periodic sales may facilitate collusion by magnifying intertemporal linking in consumers' decisions. The stability and the profitability of different sale strategies is then explored. The optimal sales discount and timing of sales are characterized. A trade-off between cartel size and aggregate profits arises.Storage, sales, collusion, cartel size, repeated games

3-D Hand Pose Estimation from Kinect's Point Cloud Using Appearance Matching

We present a novel appearance-based approach for pose estimation of a human hand using the point clouds provided by the low-cost Microsoft Kinect sensor. Both the free-hand case, in which the hand is isolated from the surrounding environment, and the hand-object case, in which the different types of interactions are classified, have been considered. The hand-object case is clearly the most challenging task having to deal with multiple tracks. The approach proposed here belongs to the class of partial pose estimation where the estimated pose in a frame is used for the initialization of the next one. The pose estimation is obtained by applying a modified version of the Iterative Closest Point (ICP) algorithm to synthetic models to obtain the rigid transformation that aligns each model with respect to the input data. The proposed framework uses a "pure" point cloud as provided by the Kinect sensor without any other information such as RGB values or normal vector components. For this reason, the proposed method can also be applied to data obtained from other types of depth sensor, or RGB-D camera

Education for Rural People: A Neglected Key To Food Security

In the world there are approximately 800 million people who live in condition of food insecurity and illiteracy. This paper shows that education is a key to food security for rural populations in developing countries. Attention is drawn to rural areas because they are traditionally more disadvantaged by national educational policies. The theoretical foundation of this research is that being educated improves rural people’s capacity to diversify assets and activities, increase productivity and income, foster resilience and competitiveness, access information on health and sanitation, strengthen social cohesion and participation: these are all essential elements to ensure food security in the long run. The main findings of this research are the following: first, the association between food insecurity and primary education is very high, while it decreases progressively with basic, secondary, and tertiary education. Such a two-way relationship is expressed through graphical tools and correlation coefficients. Second, the econometric model shows that primary education is a crucial element to reduce food insecurity in rural areas, even when compared to other factors such as access to water, health, and sanitation. Concluding from this model, an increase of access to primary education by 100% causes a decrease of food insecurity by approximately 20% or 24% depending on the definition of food insecurity and its measurement. Finally, since in most of developing countries the majority of people live in rural areas, and since it is in these areas that the largest proportion of world poverty and hunger exists, we can conclude that education for rural people is a relevant tool for promoting overall national food security.Education, Food Security, Human Development, Cross-

XNOR Neural Engine: a Hardware Accelerator IP for 21.6 fJ/op Binary Neural Network Inference

Binary Neural Networks (BNNs) are promising to deliver accuracy comparable to conventional deep neural networks at a fraction of the cost in terms of memory and energy. In this paper, we introduce the XNOR Neural Engine (XNE), a fully digital configurable hardware accelerator IP for BNNs, integrated within a microcontroller unit (MCU) equipped with an autonomous I/O subsystem and hybrid SRAM / standard cell memory. The XNE is able to fully compute convolutional and dense layers in autonomy or in cooperation with the core in the MCU to realize more complex behaviors. We show post-synthesis results in 65nm and 22nm technology for the XNE IP and post-layout results in 22nm for the full MCU indicating that this system can drop the energy cost per binary operation to 21.6fJ per operation at 0.4V, and at the same time is flexible and performant enough to execute state-of-the-art BNN topologies such as ResNet-34 in less than 2.2mJ per frame at 8.9 fps.Comment: 11 pages, 8 figures, 2 tables, 3 listings. Accepted for presentation at CODES'18 and for publication in IEEE Transactions on Computer-Aided Design of Circuits and Systems (TCAD) as part of the ESWEEK-TCAD special issu

Metastability of Logit Dynamics for Coordination Games

Logit Dynamics [Blume, Games and Economic Behavior, 1993] are randomized best response dynamics for strategic games: at every time step a player is selected uniformly at random and she chooses a new strategy according to a probability distribution biased toward strategies promising higher payoffs. This process defines an ergodic Markov chain, over the set of strategy profiles of the game, whose unique stationary distribution is the long-term equilibrium concept for the game. However, when the mixing time of the chain is large (e.g., exponential in the number of players), the stationary distribution loses its appeal as equilibrium concept, and the transient phase of the Markov chain becomes important. It can happen that the chain is "metastable", i.e., on a time-scale shorter than the mixing time, it stays close to some probability distribution over the state space, while in a time-scale multiple of the mixing time it jumps from one distribution to another. In this paper we give a quantitative definition of "metastable probability distributions" for a Markov chain and we study the metastability of the logit dynamics for some classes of coordination games. We first consider a pure $n$-player coordination game that highlights the distinctive features of our metastability notion based on distributions. Then, we study coordination games on the clique without a risk-dominant strategy (which are equivalent to the well-known Glauber dynamics for the Curie-Weiss model) and coordination games on a ring (both with and without risk-dominant strategy)

Information Spreading in Stationary Markovian Evolving Graphs

Markovian evolving graphs are dynamic-graph models where the links among a fixed set of nodes change during time according to an arbitrary Markovian rule. They are extremely general and they can well describe important dynamic-network scenarios. We study the speed of information spreading in the "stationary phase" by analyzing the completion time of the "flooding mechanism". We prove a general theorem that establishes an upper bound on flooding time in any stationary Markovian evolving graph in terms of its node-expansion properties. We apply our theorem in two natural and relevant cases of such dynamic graphs. "Geometric Markovian evolving graphs" where the Markovian behaviour is yielded by "n" mobile radio stations, with fixed transmission radius, that perform independent random walks over a square region of the plane. "Edge-Markovian evolving graphs" where the probability of existence of any edge at time "t" depends on the existence (or not) of the same edge at time "t-1". In both cases, the obtained upper bounds hold "with high probability" and they are nearly tight. In fact, they turn out to be tight for a large range of the values of the input parameters. As for geometric Markovian evolving graphs, our result represents the first analytical upper bound for flooding time on a class of concrete mobile networks.Comment: 16 page