Quantifying echo chamber effects in information spreading over political communication networks

Echo chambers in online social networks, in which users prefer to interact only with ideologically-aligned peers, are believed to facilitate misinformation spreading and contribute to radicalize political discourse. In this paper, we gauge the effects of echo chambers in information spreading phenomena over political communication networks. Mining 12 million Twitter messages, we reconstruct a network in which users interchange opinions related to the impeachment of the former Brazilian President Dilma Rousseff. We define a continuous {political position} parameter, independent of the network's structure, that allows to quantify the presence of echo chambers in the strongly connected component of the network, reflected in two well-separated communities of similar sizes with opposite views of the impeachment process. By means of simple spreading models, we show that the capability of users in propagating the content they produce, measured by the associated spreadability, strongly depends on their attitude. Users expressing pro-impeachment sentiments are capable to transmit information, on average, to a larger audience than users expressing anti-impeachment sentiments. Furthermore, the users' spreadability is correlated to the diversity, in terms of political position, of the audience reached. Our method can be exploited to identify the presence of echo chambers and their effects across different contexts and shed light upon the mechanisms allowing to break echo chambers.Comment: 9 pages, 4 figures. Supplementary Information available as ancillary fil

Persuasion bias, social influence, and uni-dimensional opinions.

We propose a boundedly rational model of opinion formation in which individuals are subject to persuasion bias; that is, they fail to account for possible repetition in the information they receive. We show that persuasion bias implies the phenomenon of social influence, whereby one’s influence on group opinions depends not only on accuracy, but also on how well-connected one is in the social network that determines communication. Persuasion bias also implies the phenomenon of unidimensional opinions; that is, individuals’ opinions over a multidimensional set of issues converge to a single “left-right” spectrum. We explore the implications of our model in several natural settings, including political science and marketing, and we obtain a number of novel empirical implications.

Innovation Systems in the Terms of Schumpeterian Crea-tive Destruction

‘Creative destruction\u27 is one of the most important analytical tools, taking into consideration both the economic and sociological characteristics of capitalist society. According to Schumpeter, in the long term, evolution gives rise to economic develo-pment resulting from batches of innovative solutions, leading to improvements in the standard of living. The innovation activity of firms is based on supply-side factors, hence it is large en-terprises that excel in innovation since they strive to achieve a monopoly market posi-tion and above-average profits. Schumpeter attempts to combine two elements: the spread of monopolies and the con-tinuation of economic development, both occurring through innovation, which is far more important than price competition. The Schumpeterian ‘creative destruction\u27 permeates the main aspects of macroeconomic activity, not only in the long term, but also in the area of economic fluctuations, structural changes, or the functioning of markets. As a result, it becomes a factor determining changes in the economic order

Saddam Hussein is “dangerous to the extreme”: The ethics of professional commentary on public figures

People are intrinsically interested in the personalities of public figures such as the celebrities they follow, political leaders, and citizens at the center of newsworthy events. The goal of the present article is to examine the key issues that surround ethical commentary on public figures by psychologists, psychiatrists, and other mental health professionals. Public commentaries carry with them a host of issues from representing a given discipline such as psychology well, to potentially harming an individual who is discussed, to furthering public education about personality and mental health issues. For this reason such commentary deserves special consideration as to when and how it is appropriate to carry out