457 research outputs found
LIPIcs, Volume 261, ICALP 2023, Complete Volume
LIPIcs, Volume 261, ICALP 2023, Complete Volum
Essays on monetary policy
This is a summary of the four chapters that comprise this D.Phil. thesis.1 This thesis
examines two major aspects of policy. The first two chapters examine monetary policy communication. The second two examine the causes and consequences of a time-varying reaction
function of the central bank.
1. Central Bank Communication and Higher Moments
In this first chapter, I investigate which parts of central bank communication affect the
higher moments of expectations embedded in financial market pricing.
Much of the literature on central bank communication has focused on how communication
impacts the conditional expected mean of future policy. But this chapter asks how central
bank communication affects the second and third moments of the financial market’s perceived
distribution of future policy decisions. I use high frequency changes in option-prices around
Bank of England communications to show that communication affects higher moments of the
distribution of expectations. I find that the relevant communication in the case of the Bank
of England is primarily confined to the information contained in the Q&A and Statement,
rather than the longer Inflation Report.
2. Mark My Words: The Transmission of Central Bank Communication to the General Public via the Print Media
In the second chapter, jointly with James Brookes, I ask how central banks can change
their communication in order to receive greater newspaper coverage, if that is indeed an objective of theirs.
We use computational linguistics combined with an event-study methodology to measure
the extent of news coverage a central bank communication receives, and the textual features
that might cause a communication to be more (or less) likely to be considered newsworthy.
We consider the case of the Bank of England, and estimate the relationship between news
coverage and central bank communication implied by our model. We find that the interaction
between the state of the economy and the way in which the Bank of England writes its
communication is important for determining news coverage. We provide concrete suggestions
for ways in which central bank communication can increase its news coverage by improving
readability in line with our results.
3. Uncertainty and Time-varying Monetary Policy
In the third chapter, together with Michael McMahon, I investigate the links between
uncertainty and the reaction function of the Federal Reserve.
US macroeconomic evidence points to higher economic volatility being positively correlated with more aggressive monetary policy responses. This represents a challenge for “good
policy” explanations of the Great Moderation which map a more aggressive monetary response to reduced volatility. While some models of monetary policy under uncertainty can
match this comovement qualitatively, these models do not, on their own, account for the
reaction-function changes quantitatively for reasonable changes in uncertainty. We present a
number of alternative sources of uncertainty that we believe should be more prevalent in the
literature on monetary policy.
4. The Element(s) of Surprise
In the final chapter, together with Michael McMahon, I analyse the implications for monetary surprises of time-varying reaction functions.
Monetary policy surprises are driven by several separate forces. We argue that many of
the surprises in monetary policy instruments are driven by unexpected changes in the reaction
function of policymakers. We show that these reaction function surprises are fundamentally
different from monetary policy shocks in their effect on the economy, are likely endogenous
to the state, and unable to removed using current orthogonalisation procedures. As a result
monetary policy surprises should not be used to measure the effect of a monetary policy
“shock” to the economy. We find evidence for reaction function surprises in the features
of the high frequency asset price surprise data and in analysing the text of a major US
economic forecaster. Further, we show that periods in which an estimated macro model
suggests policymakers have switched reaction functions provide the majority of variation in
monetary policy surprises
Syntax-semantics interface: an algebraic model
We extend our formulation of Merge and Minimalism in terms of Hopf algebras
to an algebraic model of a syntactic-semantic interface. We show that methods
adopted in the formulation of renormalization (extraction of meaningful
physical values) in theoretical physics are relevant to describe the extraction
of meaning from syntactic expressions. We show how this formulation relates to
computational models of semantics and we answer some recent controversies about
implications for generative linguistics of the current functioning of large
language models.Comment: LaTeX, 75 pages, 19 figure
A Survey on Mapping Semi-Structured Data and Graph Data to Relational Data
The data produced by various services should be stored and managed in an appropriate format for gaining valuable knowledge conveniently. This leads to the emergence of various data models, including relational, semi-structured, and graph models, and so on. Considering the fact that the mature relational databases established on relational data models are still predominant in today's market, it has fueled interest in storing and processing semi-structured data and graph data in relational databases so that mature and powerful relational databases' capabilities can all be applied to these various data. In this survey, we review existing methods on mapping semi-structured data and graph data into relational tables, analyze their major features, and give a detailed classification of those methods. We also summarize the merits and demerits of each method, introduce open research challenges, and present future research directions. With this comprehensive investigation of existing methods and open problems, we hope this survey can motivate new mapping approaches through drawing lessons from eachmodel's mapping strategies, aswell as a newresearch topic - mapping multi-model data into relational tables.Peer reviewe
LIPIcs, Volume 274, ESA 2023, Complete Volume
LIPIcs, Volume 274, ESA 2023, Complete Volum
Fundamentals
Volume 1 establishes the foundations of this new field. It goes through all the steps from data collection, their summary and clustering, to different aspects of resource-aware learning, i.e., hardware, memory, energy, and communication awareness. Machine learning methods are inspected with respect to resource requirements and how to enhance scalability on diverse computing architectures ranging from embedded systems to large computing clusters
ShapeCoder: Discovering Abstractions for Visual Programs from Unstructured Primitives
We introduce ShapeCoder, the first system capable of taking a dataset of shapes, represented with unstructured primitives, and jointly discovering (i) useful
abstraction
functions and (ii) programs that use these abstractions to explain the input shapes. The discovered abstractions capture common patterns (both structural and parametric) across a dataset, so that programs rewritten with these abstractions are more compact, and suppress spurious degrees of freedom. ShapeCoder improves upon previous abstraction discovery methods, finding better abstractions, for more complex inputs, under less stringent input assumptions. This is principally made possible by two methodological advancements: (a) a shape-to-program recognition network that learns to solve sub-problems and (b) the use of e-graphs, augmented with a conditional rewrite scheme, to determine when abstractions with complex parametric expressions can be applied, in a tractable manner. We evaluate ShapeCoder on multiple datasets of 3D shapes, where primitive decompositions are either parsed from manual annotations or produced by an unsupervised cuboid abstraction method. In all domains, ShapeCoder discovers a library of abstractions that captures high-level relationships, removes extraneous degrees of freedom, and achieves better dataset compression compared with alternative approaches. Finally, we investigate how programs rewritten to use discovered abstractions prove useful for downstream tasks
Vérification efficace de systèmes à compteurs à l'aide de relaxations
Abstract : Counter systems are popular models used to reason about systems in various fields such as the analysis of concurrent or distributed programs and the discovery and verification of business processes. We study well-established problems on various classes of counter systems. This thesis focusses on three particular systems, namely Petri nets, which are a type of model for discrete systems with concurrent and sequential events, workflow nets, which form a subclass of Petri nets that is suited for modelling and reasoning about business processes, and continuous one-counter automata, a novel model that combines continuous semantics with one-counter automata. For Petri nets, we focus on reachability and coverability properties. We utilize directed search algorithms, using relaxations of Petri nets as heuristics, to obtain novel semi-decision algorithms for reachability and coverability, and positively evaluate a prototype implementation. For workflow nets, we focus on the problem of soundness, a well-established correctness notion for such nets. We precisely characterize the previously widely-open complexity of three variants of soundness. Based on our insights, we develop techniques to verify soundness in practice, based on reachability relaxation of Petri nets. Lastly, we introduce the novel model of continuous one-counter automata. This model is a natural variant of one-counter automata, which allows reasoning in a hybrid manner combining continuous and discrete elements. We characterize the exact complexity of the reachability problem in several variants of the model.Les systèmes à compteurs sont des modèles utilisés afin de raisonner sur les systèmes
de divers domaines tels l’analyse de programmes concurrents ou distribués, et
la découverte et la vérification de systèmes d’affaires. Nous étudions des problèmes
bien établis de différentes classes de systèmes à compteurs. Cette thèse se penche sur
trois systèmes particuliers : les rĂ©seaux de Petri, qui sont un type de modèle pour les systèmes discrets Ă
événements concurrents et séquentiels ; les « réseaux de processus », qui forment une sous-classe des réseaux de Petri
adaptée à la modélisation et au raisonnement des processus d’affaires ; les automates continus à un compteur, un nouveau modèle qui combine une
sémantique continue à celles des automates à un compteur.
Pour les réseaux de Petri, nous nous concentrons sur les propriétés d’accessibilité
et de couverture. Nous utilisons des algorithmes de parcours de graphes, avec
des relaxations de réseaux de Petri comme heuristiques, afin d’obtenir de nouveaux
algorithmes de semi-décision pour l’accessibilité et la couverture, et nous évaluons
positivement un prototype.
Pour les «réseaux de processus», nous nous concentrons sur le problème de validité,
une notion de correction bien établie pour ces réseaux. Nous caractérisions
précisément la complexité calculatoire jusqu’ici largement ouverte de trois variantes
du problème de validité. En nous basant sur nos résultats, nous développons des techniques
pour vérifier la validité en pratique, à l’aide de relaxations d’accessibilité dans
les réseaux de Petri. Enfin, nous introduisons le nouveau modèle d’automates continus à un compteur. Ce modèle est une variante naturelle des automates à un compteur, qui permet de
raisonner de manière hybride en combinant des éléments continus et discrets. Nous
caractérisons la complexité exacte du problème d’accessibilité dans plusieurs variantes
du modèle
Computer Aided Verification
This open access two-volume set LNCS 13371 and 13372 constitutes the refereed proceedings of the 34rd International Conference on Computer Aided Verification, CAV 2022, which was held in Haifa, Israel, in August 2022. The 40 full papers presented together with 9 tool papers and 2 case studies were carefully reviewed and selected from 209 submissions. The papers were organized in the following topical sections: Part I: Invited papers; formal methods for probabilistic programs; formal methods for neural networks; software Verification and model checking; hyperproperties and security; formal methods for hardware, cyber-physical, and hybrid systems. Part II: Probabilistic techniques; automata and logic; deductive verification and decision procedures; machine learning; synthesis and concurrency. This is an open access book
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