Augmented Slepians: Bandlimited Functions that Counterbalance Energy in Selected Intervals

Slepian functions provide a solution to the optimization problem of joint time-frequency localization. Here, this concept is extended by using a generalized optimization criterion that favors energy concentration in one interval while penalizing energy in another interval, leading to the "augmented" Slepian functions. Mathematical foundations together with examples are presented in order to illustrate the most interesting properties that these generalized Slepian functions show. Also the relevance of this novel energy-concentration criterion is discussed along with some of its applications

The herd moves? Emergence and self-organization in collective actors?

The puzzle about collective actors is in the focus of this contribution. The first section enters into the question of the adequateness and inadequateness of reductionist explanations for the description of entities. The considerations in this part do not draw on systems and hence not on principles of self-organisation, because this concept necessitates a systemic view. In other words, the first section discusses reductionism and holism on a very general level. The scope of these arguments goes far beyond self-organising systems. Pragmatically, these arguments will be discussed within the domain of corporative actors. Emergence is a concept embedded in system theory. Therefore, in the second part the previous general considerations about holism are integrated with respect to the concept “emergence”. In order to close the argument by exactly characterising self-organising systems and giving the conceptual link between self-organisation and emergence – which is done in the section four – the third section generally conceptualises systems. This conceptualisation is independent of whether these systems are self-organising or not. Feedback loops are specified as an essential component of systems. They establish the essential precondition of system-theoretic models where causes may also be effects and vice versa. System-theory is essential for dynamic models like ecological models and network thinking. In the fourth part mathematical chaos-theory bridges the gap between the presentation of systems in general and the constricted consideration of self-organising systems. The capability to behave or react chaotically is a necessary precondition of self-organisation. Nevertheless, there are striking differences in the answers given from theories of self-organisation in biology, economics or sociology on the question “What makes the whole more than the sum of its parts?” The fracture seems particularly salient at the borderline between formal-mathematical sciences like natural sciences including economy and other social sciences like sociology, for instance in the understanding and conceptualisation of “chaos” or “complexity”. Sometimes it creates the impression that originally well defined concepts from mathematics and natural science are metaphorically used in social sciences. This is a further reason why this paper concentrates on conceptualisations of self-organisation from natural sciences. The fifth part integrates the arguments from a system-theoretic point of view given in the three previous sections with respect to collective and corporative actors. Due to his prominence all five sections sometimes deal with the sociological system theory by Niklas Luhmann, especially in those parts with rigorous and important differences between his conception and the view given in this text. Despite Luhmann’s undoubted prominence in sociology, the present text strives for a more analytical and formal understanding of social systems and tries to find a base for another methodological approach.

Comparative Financial Systems: A Survey

What is a Financial System? The purpose of a financial system is to channel funds from agents with surpluses to agents with deficits. In the traditional literature there have been two approaches to analyzing this process. The first is to consider how agents interact through financial markets. The second looks at the operation of financial intermediaries such as banks and insurance companies. Fifty years ago, the financial system could be neatly bifurcated in this way. Rich households and large firms used the equity and bond markets, while less wealthy households and medium and small firms used banks, insurance companies and other financial institutions. Table 1, for example, shows the ownership of corporate equities in 1950. Households owned over 90 percent. By 2000 it can be seen that the situation had changed dramatically. By then households held less than 40 percent, nonbank intermediaries, primarily pension funds and mutual funds, held over 40 percent. This change illustrates why it is no longer possible to consider the role of financial markets and financial institutions separately. Rather than intermediating directly between households and firms, financial institutions have increasingly come to intermediate between households and markets, on the one hand, and between firms and markets, on the other. This makes it necessary to consider the financial system as an irreducible whole. The notion that a financial system transfers resources between households and firms is, of course, a simplification. Governments usually play a significant role in the financial system. They are major borrowers, particularly during times of war, recession, or when large infrastructure projects are being undertaken. They sometimes also have significant amounts of funds. For example, when countries such as Norway and many Middle Eastern States have access to large amounts of natural resources (oil), the government may acquire large trust funds on behalf of the population. In addition to their roles as borrowers or savers, governments usually play a number of other important roles. Central banks typically issue fiat money and are extensively involved in the payments system. Financial systems with unregulated markets and intermediaries, such as the US in the late nineteenth century, often experience financial crises (Gorton (1988) and Calomiris and Gorton (1991)). The desire to eliminate these crises led many governments to intervene in a significant way in the financial system. Central banks or some other regulatory authority are charged with regulating the banking system and other intermediaries, such as insurance companies. So in most countries governments play an important role in the operation of financial systems. This intervention means that the political system, which determines the government and its policies, is also relevant for the financial system. There are some historical instances where financial markets and institutions have operated in the absence of a well-defined legal system, relying instead on reputation and other implicit mechanisms. However, in most financial systems the law plays an important role. It determines what kinds of contacts are feasible, what kinds of governance mechanisms can be used for corporations, the restrictions that can be placed on securities and so forth. Hence, the legal system is an important component of a financial system. A financial system is much more than all of this, however. An important pre-requisite of the ability to write contracts and enforce rights of various kinds is a system of accounting. In addition to allowing contracts to be written, an accounting system allows investors to value a company more easily and to assess how much it would be prudent to lend to it. Accounting information is only one type of information (albeit the most important) required by financial systems. The incentives to generate and disseminate information are crucial features of a financial system. Without significant amounts of human capital it will not be possible for any of these components of a financial system to operate effectively. Well-trained lawyers, accountants and financial professionals such as bankers are crucial for an effective financial system, as the experience of Eastern Europe demonstrates. The literature on comparative financial systems is at an early stage. Our survey builds on previous overviews by Allen (1993), Allen and Gale (1995) and Thakor (1996). These overviews have focused on two sets of issues. Normative: How effective are different types of financial systems at various functions? Positive: What drives the evolution of the financial system? The first set of issues of considered in sections 2-6, which focus on issues of investment and saving, growth, risk sharing, information provision and corporate governance, respectively. Section 7 considers the influence of law and politics on the financial system while Section 8 looks at the role financial crises have had in shaping the financial system. Section 9 contains concluding remarks.

The brain, self and society: a social-neuroscience model of predictive processing.

This paper presents a hypothesis about how social interactions shape and influence predictive processing in the brain. The paper integrates concepts from neuroscience and sociology where a gulf presently exists between the ways that each describe the same phenomenon - how the social world is engaged with by thinking humans. We combine the concepts of predictive processing models (also called predictive coding models in the neuroscience literature) with ideal types, typifications and social practice - concepts from the sociological literature. This generates a unified hypothetical framework integrating the social world and hypothesised brain processes. The hypothesis combines aspects of neuroscience and psychology with social theory to show how social behaviors may be "mapped" onto brain processes. It outlines a conceptual framework that connects the two disciplines and that may enable creative dialogue and potential future research.St John's College Cambridge Annual Fun

von Neumann-Morgenstern and Savage Theorems for Causal Decision Making

Causal thinking and decision making under uncertainty are fundamental aspects of intelligent reasoning. Decision making under uncertainty has been well studied when information is considered at the associative (probabilistic) level. The classical Theorems of von Neumann-Morgenstern and Savage provide a formal criterion for rational choice using purely associative information. Causal inference often yields uncertainty about the exact causal structure, so we consider what kinds of decisions are possible in those conditions. In this work, we consider decision problems in which available actions and consequences are causally connected. After recalling a previous causal decision making result, which relies on a known causal model, we consider the case in which the causal mechanism that controls some environment is unknown to a rational decision maker. In this setting we state and prove a causal version of Savage's Theorem, which we then use to develop a notion of causal games with its respective causal Nash equilibrium. These results highlight the importance of causal models in decision making and the variety of potential applications.Comment: Submitted to Journal of Causal Inferenc

Fabrication and analogue applications of nanoSQUIDs using Dayem bridge junctions

We report here recent work at the U.K. National Physical Laboratory on developing nanoscale SQUIDs using Dayem bridge Josephson junctions. The advantages are simplicity of fabrication, exceptional low-noise performance, toward the quantum limit, and a range of novel applications. Focused ion beam patterned Nb SQUID, possessing exceptionally low noise (∼200 nΦ0/Hz1/2 above 1 kHz), and operating above 4.2 K can be applied to measurement of nanoscale magnetic objects or coupled to nanoelectromechanical resonators, as well as single particle detection of photons, protons, and ions. The limited operating temperature range may be extended by exposing the Dayem bridges to carefully controlled ion beam implantation, leading to nonreversible changes in junction transition temperature.The work reported here was supported in part by the EMRP projects ‘MetNEMS’ NEW-08 and ‘BioQUART’SIB-06. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union

Anthropocene, Capitalocene, Machinocene: Illusions of instrumental reason

In their seminal work, Dialectics of Enlightenment, Horkheimer and Adorno interpreted capitalism as the irrational monetization of nature. In the present work, I analyze three 21st century concepts, Anthropocene, Capitalocene and Machinocene, in light of Horkheimer and Adorno’s arguments and recent arguments from the philosophy of biology. The analysis reveals a remarkable prescience of the term “instrumental reason”, which is present in each of the three concepts in a profound and cryptic way. In my interpretation, the term describes the propensity of science based on the notion of physicalism to interpret nature as the machine analyzable and programmable by the human reason. As a result, the Anthropocene concept is built around the mechanicist model, which may be presented as the metaphor of the car without brakes. In a similar fashion, the Machinocene concept predicts the emergence of the mechanical mind, which will dominate nature in the near future. Finally, the Capitalocene concept turns a perfectly rational ambition to expand knowledge into an irrational obsession with over-knowledge, by employing the institutionalized science as the engine of capitalism without brakes. The common denominator of all three concepts is the irrational propensity to legitimize self-destruction. Potential avenues for countering the effects of “instrumental reason” are suggested

A Review of IPO Activity, Pricing, and Allocations

We review the theory and evidence on IPO activity: why firms go public, why they reward first-day investors with considerable underpricing, and how IPOs perform in the long run. Our perspective on the literature is three-fold: First, we believe that many IPO phenomena are not stationary. Second, we believe research into share allocation issues is the most promising area of research in IPOs at the moment. Third, we argue that asymmetric information is not the primary driver of many IPO phenomena. Instead, we believe future progress in the literature will come from non-rational and agency conflict explanations. We describe some promising such alternatives.