1,142 research outputs found
Money-back guarantees in individual pension accounts : evidence from the German pension reform
The German Retirement Saving Act instituted a new funded system of supplementary pensions coupled with a general reduction in the level of state pay-as-you-go old-age pensions. In order to qualify for tax relief, the providers of supplementary savings products must offer a guarantee of the nominal value at retirement of contributions paid into these saving accounts. This paper explores how this "money-back" guarantee works and evaluates alternative designs for guarantee structures, including a life cycle model (dynamic asset allocation), a plan with a pre-specified blend of equity and bond investments (static asset allocation), and some type of portfolio insurance. We use a simulation methodology to compare hedging effectiveness and hedging costs associated with the provision of the money-back guarantee. In addition, the guarantee has important implications for regulators who must find an appropriate solvency system for such saving schemes. This version June 17, 2002 . Klassifikation: G11, G23, G2
Two approaches to self-love: Hutcheson and Butler
This paper contrasts Frankfurtâs characterisation of self-love as disinterested with the predominant 18th-century view on self-love as interested. Ttwo senses of the term âinterestâ are distinguished
to discuss two fundamentally different readings of the claim that self-love promotes the agentâs interest. This allows characterising two approaches to self-love, which are found in Hutchesonâs and in Bbutlerâs writings. Hutcheson sees self-love as a source of hedonistic motives, which can be calm or passionate. Bbutler sees it as a general affection of rational beings in the sense of a kind of love of oneâs real nature
\theta^PMNS_13 = \theta_C / \sqrt2 from GUTs
The recent observations of the leptonic mixing angle \theta^PMNS_13 are
consistent with \theta^PMNS_13 = \theta_C / \sqrt2 (with \theta_C being the
Cabibbo angle \theta^CKM_12). We discuss how this relation can emerge in Grand
Unified Theories (GUTs) via charged lepton corrections. The key ingredient is
that in GUTs the down-type quark Yukawa matrix and the charged lepton Yukawa
matrix are generated from the same set of GUT operators, which implies that the
resulting entries are linked and differ only by group theoretical Clebsch
factors. This allows a link \theta^e_12 = \theta_C to be established, which can
induce \theta^PMNS_13 = \theta_C / \sqrt2 provided that the 1-3 mixing in the
neutrino mass matrix is much smaller than \theta_C. We find simple conditions
under which \theta^PMNS_13 = \theta_C / \sqrt2 can arise via this link in SU(5)
GUTs and Pati-Salam models. We also discuss possible corrections to this
relation. Using lepton mixing sum rules different neutrino mixing patterns can
be distinguished by their predictions for the Dirac CP phase \delta^PMNS.Comment: v3: 18 pages, section on corrections to exact relation adde
Causal Boxes: Quantum Information-Processing Systems Closed under Composition
Complex information-processing systems, for example quantum circuits,
cryptographic protocols, or multi-player games, are naturally described as
networks composed of more basic information-processing systems. A modular
analysis of such systems requires a mathematical model of systems that is
closed under composition, i.e., a network of these objects is again an object
of the same type. We propose such a model and call the corresponding systems
causal boxes.
Causal boxes capture superpositions of causal structures, e.g., messages sent
by a causal box A can be in a superposition of different orders or in a
superposition of being sent to box B and box C. Furthermore, causal boxes can
model systems whose behavior depends on time. By instantiating the Abstract
Cryptography framework with causal boxes, we obtain the first composable
security framework that can handle arbitrary quantum protocols and relativistic
protocols.Comment: 44+24 pages, 16 figures. v3: minor edits based on referee comments,
matches published version up to layout. v2: definition of causality weakened,
new reference
Toward an Algebraic Theory of Systems
We propose the concept of a system algebra with a parallel composition
operation and an interface connection operation, and formalize
composition-order invariance, which postulates that the order of composing and
connecting systems is irrelevant, a generalized form of associativity.
Composition-order invariance explicitly captures a common property that is
implicit in any context where one can draw a figure (hiding the drawing order)
of several connected systems, which appears in many scientific contexts. This
abstract algebra captures settings where one is interested in the behavior of a
composed system in an environment and wants to abstract away anything internal
not relevant for the behavior. This may include physical systems, electronic
circuits, or interacting distributed systems.
One specific such setting, of special interest in computer science, are
functional system algebras, which capture, in the most general sense, any type
of system that takes inputs and produces outputs depending on the inputs, and
where the output of a system can be the input to another system. The behavior
of such a system is uniquely determined by the function mapping inputs to
outputs. We consider several instantiations of this very general concept. In
particular, we show that Kahn networks form a functional system algebra and
prove their composition-order invariance.
Moreover, we define a functional system algebra of causal systems,
characterized by the property that inputs can only influence future outputs,
where an abstract partial order relation captures the notion of "later". This
system algebra is also shown to be composition-order invariant and appropriate
instantiations thereof allow to model and analyze systems that depend on time
Linking information reconciliation and privacy amplification
Information reconciliation allows two parties knowing correlated random variables, such as a noisy version of the partner's random bit string, to agree on a shared string. Privacy amplification allows two parties sharing a partially secret string about which an opponent has some partial information, to distill a shorter but almost completely secret key by communicating only over an insecure channel, as long as an upper bound on the opponent's knowledge about the string is known. The relation between these two techniques has not been well understood. In particular, it is important to understand the effect of side-information, obtained by the opponent through an initial reconciliation step, on the size of the secret key that can be distilled safely by subsequent privacy amplification. The purpose of this paper is to provide the missing link between these techniques by presenting bounds on the reduction of the RĂ©nyi entropy of a random variable induced by side-information. We show that, except with negligible probability, each bit of side-information reduces the size of the key that can be safely distilled by at most two bits. Moreover, in the important special case of side-information and raw key data generated by many independent repetitions of a random experiment, each bit of side-information reduces the size of the secret key by only about one bit. The results have applications in unconditionally secure key agreement protocols and in quantum cryptograph
List objects and recursive algorithms in elementary topoi
The paper generalizes results of [B] by formulating their background in
categories with a sufficiently rich internal logic, e. g. elementary topoi,
using the well known initial algebra approach. Thus the right setting for
program transformations in the sense of [B] is given by embedding them into
the generalisation of primitive recursion over the naturals in the sense of
[F] to lists. Particularly there is a simple concept of tail recursion, hence
an outline on a systematic transformation of naive recursive programs into
tail recursive i. e. more efficient iterative forms
Contexts of religious tolerance: New perspectives from early modern Britain and beyond
This article is an introduction to a special issue on âContexts of Religious Tolerance: New Perspectives from Early Modern Britain and Beyondâ, which contains essays on the contributions to the debates on tolerance by non-canonical philosophers and theologians, mainly from seventeenth- and eighteenth-century Scotland and England. Among the studied authors are the Aberdeen Doctors, Samuel Rutherford, James Dundas, John Finch, George Keith, John Simson, Archibald Campbell, Francis Hutcheson, George Turnbull and John Witherspoon. The introduction draws attention to several methodological points connected to the decision to look at the debates on tolerance through the prism of rarely studied authors. It then presents the essays, which offer novel perspectives by analysing and contextualising political, religious and moral treatments of tolerance. These are tied especially to debates on the articles of faith and on their status, on confessions of faith and their role in the quest for orthodoxy, on liberty of conscience, and on the relation between church and state
Editorial: Journalism, Activism, and Social Media: Exploring the Shifts in Journalistic Roles, Performance, and Interconnectedness
The emergence of the Hybrid Media System (Chadwick, 2017) has changed the actor constellations between political journalism, active members of the audience, and sources. How journalism responds to activism, pressure from politics, and emerging forms of connective action around news events is an important theme in journalism research. This thematic issue brings together seven articles that look at these developments from different angles in a rapidly changing communication ecosystem. The focus is on journalistic authority and legitimacy, journalism and interpretive communities, and changes concerning journalistic roles and practices
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