Does Overconfidence Bias Explain Volatility During the Global Financial Crisis?

This paper explores the problem of the current global financial crisis, using a behavioral perspective. Particularly, the main objective of this paper is to test whether overconfidence bias can explain excessive volatility witnessed during global financial crisis in developed and emerging equity markets. Empirical results of EGARCH estimated models show an asymmetric effect of volatility for all equity market indexes. The relation between excessive trading volume of overconfident investors and excessive prices volatility is then estimated. The results indicate that conditional volatility is positively related to trading volume caused by overconfidence bias. This finding provides strong statistical support to the presence of overconfidence bias among investors in developed and emerging stocks markets. This cognitive bias contributes to the exceptional financial instability that erupted in 2008. However, during the subprime financial crisis period overconfidence bias cannot explain volatility because of the loss of confidence by investors in financial markets.     

Overconfident health workers provide lower quality healthcare

While a growing body of evidence suggests that healthcare workers in low and middle-income countries often provide poor quality of care, the reasons behind such low performance remain unclear. The literature on medical decision-making suggests that cognitive biases, or failures related to the way healthcare providers think, explain many diagnostic errors. This study investigates whether one cognitive bias, overconfidence, defined as the tendency to overestimate one’s performance relative to others, is associated with the low quality of care provided in Senegal. We link survey data on the overconfidence of health workers to objective measures of the quality of care they provide to standardised patients – enumerators who pose as real patients and record details of the consultation. We find that about a third of providers are overconfident – meaning that they overestimate their own abilities relative to their peers. We then show that overconfident providers are 26% less likely to manage patients correctly and exert less effort in clinical practice. These results suggest that the low levels of quality of care observed in some settings could be partly explained by the cognitive biases of providers, such as overconfidence. Policies that encourage adequate supervision and feedback to healthcare workers might reduce such failures in clinical decision-making.     

Overfeed the Bold,Starve the Cowardly: A Legend or Reality?

Although the negative effects of overconfidence are more likely to be mentioned in the literature, some researchers have argued that the benefits of overconfidence may outweigh its costs. We attempted to explore the positive effects of overconfidence in competitive situations. We had participants compete against fake opponents who were overconfident and then measured their competitive performance in two studies. In Study 1 we examined the effects of overconfidence on competitive performance in a competitive situation and the possible mechanism for this overconfidence. In Study 2 we investigated the characteristics of the performance in a competition after a mismatch between the level of confidence and the fake opponent’s actual competence was revealed. Our results indicated that overconfident individuals tend to be perceived as more competent and more likely to benefit in the process of competition. Even after a mismatch between the level of confidence and the real competence was revealed, the overconfident individuals were not punished in that they made as much money as the less overconfident and still got higher competence ratings. Together those studies suggested that overconfidence has its advantages in competitive situations.     

The value of being precise

This study investigates how individuals assess imprecise information. We focus on two essential dimensions of decision under uncertainty, outcomes and probabilities, and their respective precision. We believe the precision of information is highly relevant in the investment setting, as reflected in the well-known “home (familiarity) bias”, and the outcome and probability dimensions, separately or jointly, may affect investors’ knowledge of uncertainty and perceived risk of the investment options, and subsequently affect investors’ choices. To test this conjecture, we conducted three experiments. Our results show that 1) participants demonstrate a pattern of preference for precision and aversion of extreme vagueness and associate vagueness with higher perceived risk and lower investment (experiments one and two); 2) participants prefer vague outcome information to vague probability information (experiment two); 3) familiarity indeed positively affects the precision of estimated values, but this association is stronger for the outcome dimension than for probabilities (experiment three). Our results confirm that precision in information, especially in the outcome dimension has an impact on investors’ resource allocation choices.     

Overconfidence,omens and gender heterogeneity: Results from a field experiment

We investigate whether overconfidence is affected by superstitious beliefs and whether the effect is heterogeneous according to gender. With this aim, we run a field experiment involving about 700 Italian students. According to widespread superstitions, some numbers are considered lucky while others are thought of as unlucky. In our experiment, we exploited this by randomly assigning students to numbered seats in their written exam. At the end of the examination, we asked students the grade they expected to get. We find that students tend to be overconfident about their performance at the exam and that their overconfidence is positively affected by being assigned to a lucky number. Interestingly, males and females react differently: females’ overconfidence tends to be negatively affected when assigned to unlucky numbers, while they are not affected by being assigned to lucky numbers; males are not affected by being assigned to unlucky numbers but are more overconfident when assigned to lucky numbers.     

Overconfidence in absolute and relative performance: The regression hypothesis and Bayesian updating

Studies have found that people are overconfident in estimation involving difficult tasks but underconfident in easy tasks. Conversely, they are overconfident in placing themselves in easy tasks but underconfident in hard tasks. These findings can be explained by a regression hypothesis that implies random errors in estimation as well as by rational Bayesian updating (that implies no random error). We test these hypotheses in five experiments. We find overconfidence in estimation involving hard tasks but underconfidence in easy tasks. However, for placement (involving both easy and hard tasks) we find no overconfidence, regression effects due to low and high anchor points, and extreme underconfidence when people choose between multiple alternatives. On the other hand, when given precise information about absolute performance, people’s re-assessments of relative performance are consistent with the Bayesian model. Since placement judgments are important in many competitive settings, our results emphasize the need for more research to identify their determinants.     

‘Resistance: Which Way the Future?’ A dual-screen installation related to the theme of disability and eugenics

This paper reports the part findings of an evaluation of a dual-screen installation entitled ‘Resistance: Which Way the Future?’ by the writer and director Liz Crow. Central to the installation is the experience of disabled people during the Holocaust period, the values underpinning this neglected period of history and how this relates to understanding the experiences of disabled people today. Simultaneously, this paper raises issue with a previous comment which suggested that disabled people and eugenics are a form of ‘emotive rhetoric’. On the contrary, this paper asserts that the link between eugenics and disability cannot be overstated, and is a significant moment in history where the lived experiences of disabled people – people described as having ‘learning difficulties’, surviving artefacts, and recorded testimonies – have still yet to be explored.     

Change we can believe in: Comparing longitudinal network models on consistency,interpretability and predictive power

While several models for analysing longitudinal network data have been proposed, their main differences, especially regarding the treatment of time, have not been discussed extensively in the literature. However, differences in treatment of time strongly impact the conclusions that can be drawn from data. In this article we compare auto-regressive network models using the example of TERGMs – a temporal extensions of ERGMs – and process-based models using SAOMs as an example. We conclude that the TERGM has, in contrast to the ERGM, no consistent interpretation on tie-level probabilities, as well as no consistent interpretation on processes of network change. Further, parameters in the TERGM are strongly dependent on the interval length between two time-points. Neither limitation is true for process-based network models such as the SAOM. Finally, both compared models perform poorly in out-of-sample prediction compared to trivial predictive models.     

Phototextuality: photography,fiction, criticism

Ever since the advent of the medium in the mid-nineteenth century, photography and literature have been involved in an almost constant dialogue and process of intersemiotic cross-fertilisation. The scholarly field that has recently begun to develop around the critical study of this kind of aesthetic border crossing – what will here be called ‘phototextuality’ – is as burgeoning as it is multidisciplinary, spanning over 150 years of literary, artistic, and cultural history. In this article – conceived as a ‘state of the art’ of contemporary phototextual practice – the author proposes to clarify our understanding of what a phototext is and does by focusing on three particular manifestations of the trend: namely, narrative photographs, photographically engaged fictions and a particularly stunning work of critical inquiry that embodies, as much as it examines, the image–text paradigm.     

9-11 and Its Anxious Phantoms

Abstract

“Metaphysical mutations – that is to say, global transformation in the values to which the majority subscribe – are rare in the history of humanity. The rise of Christianity might be cited as an example.

Once a metaphysical mutation has arisen, it tends to move inexorably toward its logical conclusion. Heedlessly, it sweeps away economic and political systems, aesthetic judgments and social hierarchies. No human agency can halt its progress – nothing except another metaphysical mutation.”     

Family Genealogy: A Sociological Imagination Reveals Intersectional Relations

This article depicts everyday family genealogy as a vehicle for the sociological imagination that links personal biography to social–historical contexts across generations. As genealogists construct current from past identities, they engage a sociological imagination that potentially enables them to grasp how intersectionality – gender, race, ethnic, sexuality, nation, class, and age relations – is articulated through history. The key aims here are: (1) to provide background conditions behind the growth of genealogy; (2) to reveal how doing and studying family genealogy engages a sociological imagination that can be a vehicle for perceiving the intersectional underpinnings of social memories. Genealogy can be seen as a political practice where race-class-gender within social memories can contribute to diverse stories from new standpoints in American history.     

Promiscuous Intimacies: Rethinking the History of American Casual Sex

Casual sex has become a cultural commonplace since it was named in the 1960s and later became associated with the US college sex phenomenon of “hooking up”. However, contemporary accounts of this sexual practice are curiously lacking in historical perspective. This article explores this modern history, both before and after uncommitted, non‐romantic, sexual encounters – sex for sex's sake – were named as casual sex. It agues that studies that contrast the increased “sexual possibilities” of hookup sex to the assumed restrictive practices of an earlier era distort both the restrictions of the earlier period and the freedoms of the latter.     

Endocrine state is the physical manifestation of subjective beliefs

Over the past two decades, economists have begun to incorporate evidence from neuroscience into applied economic research. While some progress has been made, the wider economics profession has yet to embrace the new field of “neuroeconomics.” I argue here that a broad reconciliation of emerging evidence from neuroscience with conventional economic decision theory can be achieved by emphasizing the critical role of neuroendocrine signaling molecules and their receptors. Many of these molecules are amenable to measurement and manipulation in laboratory settings, and most have – when viewed in light of their natural history – a parsimonious interpretation as representing what economists refer to as subjective beliefs.     

From Limited to Active Engagement: Mexico’s Emigration Policies from a Foreign Policy Perspective (2000–2006)

Mexico’s emigration policies – including the state’s engagement with the diaspora, the discourse in relation to emigrants, the responses to U.S. migration policies and legislation, and the priority given to the issue in the national and bilateral agendas – have undergone a process of transformation since the late 1980s and particularly after 2000. From a history of generally limited engagement in terms of responding to U.S. policies and a traditional interpretation of consular protection activities, Mexico has gradually developed more active policies in relation to the diaspora and began a process of redefining its position on emigration. In addition to the processes of political change in Mexico and the growing impact of migrants’ transnational activities, changes in Mexico’s emigration policies are also a result of transformations in foreign policy principles and strategies, mainly as a result of the evolution of U.S.‐Mexico relations since the late 1980s and particularly since NAFTA. These findings demonstrate the significance of international factors – namely host state – sending state relations and foreign policy interests, discourse, and traditions – in the design and implementation of migration policies and the need to develop multi‐level analyses to explain states’ objectives, interests, and capacities in the management of migration.     

Anti‐American Resistance in Latin America: An Issue of Sovereignty,Militarization, and Neoliberalism

In recent years, Latin America has experienced a shift toward the left, bringing attention to the significance of US‐Latin America relations and the history of resistance that these dynamics have engendered. While the voices and faces of these resistance movements may be perceived as new, their roots date back to the turn of the 20th century. The emergence of an anti‐American narrative from diverse sectors in Latin America as part of a response to US policies – political, military, and economic – provides an opportunity for reflection on this history. By examining US policy towards Latin America, and the emerging forms of resistance from local sectors in response to policies on sovereignty, militarism, and neoliberalism, we can better situate the ‘anti‐American’ resistance movements of today.     

Geopolitical-economic conflict and network infrastructures

This article explicates three basic aspects of the conflicted history of transnational communications networks: How extraterritorial communications have functioned since the nineteenth century as a primary axis of expansion for a transnationalizing capitalism; how geopolitical pressures and rivalries have helped break down and reconstitute network infrastructures; and how contemporary US–China relations in respect to the Internet may be set within this historical framework. The longstanding dominance of the United States over extraterritorial networks was itself a historical outcome, and today it faces escalating – but still far from successful – challenges.     

Rapidly diffusing innovation: whether the history of the Internet points the way for hydrogen energy

This paper identifies conditions for the rapid diffusion of what may be part of the solution for global sustainable energy – hydrogen – by drawing a comparison with the contemporary history of the Internet. The Cold War drove the take-off of the Internet and state regulation ensured that the market on which its rapid diffusion came to depend was not controlled by corporations. To take-off and start to diffuse, hydrogen energy could similarly have to be considered a “public good”. However, the comparison with the Internet reveals differences too. The Internet diffused rapidly among the public at low cost to individual users, starting in the mid 1980s and kicking off in the 1990s. To achieve affordable hydrogen transport in the long term, many drivers might have to forgo cars for public transport. Moreover, global sustainable energy demands cooperation between nations rather than the conflict that spurred the Internet.     

Psychological mechanisms of investors in Chinese Stock Markets

The study investigated the psychological mechanisms of risky investment behaviors in Chinese Stock Markets. A 42-item questionnaire was developed and distributed to 1547 individual investors recruited by stratified random sampling from Nan Fang Bond Company. A speculative orientation and a low level of risk perception among Chinese investors were revealed. The results also showed that investors were deficient in investment knowledge and skills. Structural equation modeling was used to generate a risk perception-mediated model for investment behaviors. We found that information from organizational/institutional level can precipitate low risk perception and policy-oriented speculation of investors, which could be accounted for by the collectivistic culture in China and may not be beneficial to risk management in Chinese Stock Markets. Suggestions were made regarding the further development of stock markets in China.     

Deciphering a Mystery: Digital Technology and the Revelation of Handwritten Texts by Marcel Nadjari and Other Members of the Jewish Sonderkommando in Auschwitz-Birkenau

ABSTRACT

Jewish Sonderkommando's handwritten notes – found among the earth and ashes – are key documents of Holocaust history. But their degree of preservation is poor. Digital technology comes to the rescue to restore the legibility of these documents potentially lost to history. This article provides some examples of the successful application of image processing, which considerably increases the sharpness of the text. Special filters and approaches managed to increase by fourfold the number of pages from Marcel Nadjari's notes that could be read before. The deciphered fragments of Nadjari's notes not only allow us to better understand the meaning of the entire document, but also make a connection to another Nadjari text, thus yielding a new, much deeper, understanding of both the author himself, the particular fate of Greek Jews in the Holocaust, and also their role in the life and death of the Jewish Sonderkommando in Auschwitz–Birkenau.     

Speaking trajectories: Meaghan Morris,antipodean theory and Australian cultural studies

Over the last 30 years, the term discourse has spread throughout both the social sciences and the humanities. There is a widespread consensus that the current usage of the term ‘discourse’ originated with Foucault. This paper has three related goals: first, it demonstrates that the current usage of ‘discourse‘ did not originate with Foucault, and in some ways contradicts his own limited technical usage. Second, an intellectual history is presented that explains where the term originated – in French and British theory of the 1960s and 1970s – and how it was propagated and transformed by Anglo-American cultural studies theorists. By extending this intellectual history through the 1990s, the paper documents how Anglo-American scholars increasingly began to attribute the concept to Foucault, and how this has contributed to two important misreadings of Foucault. In conclusion, this history is drawn upon to explore and clarify several competing usages of the term in contemporary cultural studies.