A simplified stock-flow consistent dynamic model of the systemic financial fragility in the 'New Capitalism'

In the last few years, many financial analysts and heterodox economists (but even some ‘dissenters’ among orthodox economists) have referred to the contribution of Hyman P. Minsky as fundamental to understanding the current crisis. However, it is well-known that the traditional formulation of Minsky’s ‘financial instability hypothesis’ shows serious internal logical problems. Furthermore, Minsky’s analysis of capitalism must be updated on the basis of the deep changes which, during the last three decades, have concerned the world economy. In order to overcome these theoretical and empirical troubles, this paper, first, introduces the reader to the ‘mechanics’ of the financial instability theory, according to the formulation of the traditional Minskian literature (section 2). Second, it shows ‘why’ Minsky’s theory cannot be regarded as a general theory of the business cycle (section 3). Third, the paper attempts to supply a simplified, but consistent, re-formulation of Minsky’s theory by inter-breeding it with inputs coming from the ‘New Cambridge’ theories and the current ‘formal Minskian literature’. The aim of this is to analyze the impact of both capital-asset inflation and consumer credit on the financial ‘soundness’ of the non-financial business sector (sections 4-7). Some concluding remarks are provided in the last part of the paper (section 8).Financial Instability; Stock-Flow Consistency; Capital-asset Inflation

D2D Data Offloading in Vehicular Environments with Optimal Delivery Time Selection

Within the framework of a Device-to-Device (D2D) data offloading system for cellular networks, we propose a Content Delivery Management System (CDMS) in which the instant for transmitting a content to a requesting node, through a D2D communication, is selected to minimize the energy consumption required for transmission. The proposed system is particularly fit to highly dynamic scenarios, such as vehicular networks, where the network topology changes at a rate which is comparable with the order of magnitude of the delay tolerance. We present an analytical framework able to predict the system performance, in terms of energy consumption, using tools from the theory of point processes, validating it through simulations, and provide a thorough performance evaluation of the proposed CDMS, in terms of energy consumption and spectrum use. Our performance analysis compares the energy consumption and spectrum use obtained with the proposed scheme with the performance of two benchmark systems. The first one is a plain classic cellular scheme, the second is a D2D data offloading scheme (that we proposed in previous works) in which the D2D transmissions are performed as soon as there is a device with the required content within the maximum D2D transmission range..

Notes for an analytical history of the political economy

This paper deals with the analytical weakness of a number of papers which are published in the journals of history of economic thought. The aim is to highlight the need to combine the historical sensibility with both the logical consistency and the formal rigour of the analysis.History of Economic Thought; Economic Methodology; Heterodox Approaches

SPoT: Representing the Social, Spatial, and Temporal Dimensions of Human Mobility with a Unifying Framework

Modeling human mobility is crucial in the analysis and simulation of opportunistic networks, where contacts are exploited as opportunities for peer-topeer message forwarding. The current approach with human mobility modeling has been based on continuously modifying models, trying to embed in them the mobility properties (e.g., visiting patterns to locations or specific distributions of inter-contact times) as they came up from trace analysis. As a consequence, with these models it is difficult, if not impossible, to modify the features of mobility or to control the exact shape of mobility metrics (e.g., modifying the distribution of inter-contact times). For these reasons, in this paper we propose a mobility framework rather than a mobility model, with the explicit goal of providing a exible and controllable tool for modeling mathematically and generating simulatively different possible features of human mobility. Our framework, named SPoT, is able to incorporate the three dimensions - spatial, social, and temporal - of human mobility. The way SPoT does it is by mapping the different social communities of the network into different locations, whose members visit with a configurable temporal pattern. In order to characterize the temporal patterns of user visits to locations and the relative positioning of locations based on their shared users, we analyze the traces of real user movements extracted from three location-based online social networks (Gowalla, Foursquare, and Altergeo). We observe that a Bernoulli process effectively approximates user visits to locations in the majority of cases and that locations that share many common users visiting them frequently tend to be located close to each other. In addition, we use these traces to test the exibility of the framework, and we show that SPoT is able to accurately reproduce the mobility behavior observed in traces. Finally, relying on the Bernoulli assumption for arrival processes, we provide a throughout mathematical analysis of the controllability of the framework, deriving the conditions under which heavy-tailed and exponentially-tailed aggregate inter-contact times (often observed in real traces) emerge

Competition without equilibrium. The 'entrepreneurial discovery' in Austrian Economic Theory

The aim of this paper is to supply both a description and an interpretation-key of the recent developments in the Austrian Economics, with particular attention for the role played by the concept of «entrepreneurial discovery». Without knowing exactly «what» he is looking for and without using a particular research method, the Austrian entre-preneur, like a modern buccaneer, peers at the horizon, waiting for new money profit opportunities.Austrian Economics; Entrepreneurial Discovery Approach; Methodological Individualism

Analysis of individual pair and aggregate inter-contact times in heterogeneous opportunistic networks

Foundational work in the area of opportunistic networks has shown that the distribution of inter-contact times between pairs of nodes has a key impact on the network properties, e.g. in terms of convergence of forwarding protocols. Specifically, forwarding protocols may yield infinite expected delay if the inter-contact time distributions present a particularly heavy tail. While these results hold for the distributions of inter-contact times between individual pairs, most of the literature uses the aggregate distribution, i.e. the distribution obtained by considering the samples from all pairs together, to characterise the properties of opportunistic networks. In this paper we analyse when this approach is correct and when it is not. We study, through an analytical model, the dependence between the individual pair and the aggregate distributions. We show that the aggregate distribution can be way different from the distributions of individual pair inter-contact times. Therefore, using the former to characterise properties that depend on the latter is not correct in general, although this is correct in some cases. We substantiate this finding by analysing the most representative distributions characterising real opportunistic networks that have been reported in the literature based on trace analysis. We study networks whose aggregate inter-contact time distribution presents a heavy tail with or without exponential cutoff. We show that a exponential cutoff in the aggregate appears when the average inter-contact times of individual pairs are finite. We also show that, when individual pairs follow Pareto distributions, the aggregate distribution consistently presents a heavy tail. However, heavy tail aggregate distributions can also emerge in networks where individual pair inter-contact times are not heavy tailed, e.g. exponential or Pareto with exponential cutoff distributions. This constitutes a reassuring result, as it means that forwarding protocols do not necessarily diverge in the quite common case of networks whose aggregate inter-contact time distribution is heavy tailed

The stability region of the delay in Pareto opportunistic networks

The intermeeting time, i.e., the time between two consecutive contacts between a pair of nodes, plays a fundamental role in the delay of messages in opportunistic networks. A desirable property of message delay is that its expectation is finite, so that the performance of the system can be predicted. Unfortunately, when intermeeting times feature a Pareto distribution, this property does not always hold. In this paper, assuming heterogeneous mobility and Pareto intermeeting times, we provide a detailed analysis of the conditions for the expectation of message delay to be finite (i.e., to converge) when social-oblivious or social-aware forwarding schemes are used. More specifically, we consider different classes of social-oblivious and social-aware schemes, based on the number of hops allowed and the number of copies generated. Our main finding is that, in terms of convergence, allowing more than two hops may provide advantages only in the social-aware case. At the same time, we show that using a multi-copy scheme can in general improve the convergence of the expected delay. We also compare social-oblivious and social-aware strategies from the convergence standpoint and we prove that, depending on the mobility scenario considered, social-aware schemes may achieve convergence while social-oblivious cannot, and vice versa. Finally, we apply the derived convergence conditions to three popular contact data sets available in the literature (Cambridge, Infocom, and RollerNet), assessing the convergence of each class of forwarding protocols in these three cases