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The aim of this article is to establish a stochastic search algorithm for neural networks based on the fractional stochastic processes {đ”đ»đĄ,đĄâ„0} with the Hurst parameter đ»â(0,1). We define and discuss the properties of fractional stochastic processes, {đ”đ»đĄ,đĄâ„0}, which generalize a standard Brownian motion. Fractional stochastic processes capture useful yet different properties in order to simulate real-world phenomena. This approach provides new insights to stochastic gradient descent (SGD) algorithms in machine learning. We exhibit convergence properties for fractional stochastic processes.
The paper âfocuses on the critique of economic rationalityâ (p. 2). The author analyses the work by Amartya Sen with a somewhat interdisciplinary approach. The author concludes that Sen has greatly shifted our paradigm of economic rationality. The nexus of ethics and economics as well as the two types of rationality (consistency versus optimization) are major contributions of Sen, according to the author. In a nutshell, Senâs work is reconfiguring economic rationality until today.
This article explores the determinants of peopleâs growth prospects in survey data as well as the impact of the European recovery fund to future growth. The focus is on the aftermath of the Corona pandemic, which is a natural limit to the sample size. We use Eurobarometer survey data and macroeconomic variables, such as GDP, unemployment, public deficit, inflation, bond yields, and fiscal spending data. We estimate a variety of panel regression models and develop a new simulation-regression methodology due to limitation of the sample size. We find the major determinant of peopleâs growth prospect is domestic GDP per capita, while European fiscal aid does not significantly matter. In addition, we exhibit with the simulation-regression method novel scientific insights, significant outcomes, and a policy conclusion alike.
Rational behavior is a standard assumption in science. Indeed, rationality is required for environmental action towards net-zero emissions or public health interventions during the SARS-CoV-2 pandemic. Yet, little is known about the elements of rationality. This paper explores a dualism of rationality comprised of optimality and consistency. By designing a new guessing game, we experimentally uncover and disentangle two building blocks of human rationality: the notions of optimality and consistency. We find evidence that rationality is largely associated to optimality and weakly to consistency. Remarkably, under uncertainty, rationality gradually shifts to a heuristic notion. Our findings provide insights to better understand human decision making.
The aim of this work is to establish and generalize a relationship between fractional partial differential equations (fPDEs) and stochastic differential equations (SDEs) to a wider class of stochastic processes, including fractional Brownian motions and sub-fractional Brownian motions with Hurst parameter H â (1/2,1). We start by establishing the connection between a fPDE and SDE via the Feynman-Kac Theorem, which provides a stochastic representation of a general Cauchy problem. In hindsight, we extend this connection by assuming SDEs with fractional and sub-fractional Brownian motions and prove the generalized Feynman-Kac formulas under a (sub-)fractional Brownian motion. An application of the theorem demonstrates, as a by-product, the solution of a fractional integral, which has relevance in probability theory.
This article studies the renewed interest surrounding sustainable public finance and the topic of tax evasion as well as the new theory of information inattention. Extending a model of tax evasion with the notion of inattention reveals novel findings about policy instruments that can be used to mitigate tax evasion. We show that the attention parameters regarding tax rates, financial penalty schemes and income levels are as important as the level of the detection probability and the financial penalty incurred. Thus, our theory recommends the enhancement of sustainability in public policy, particularly in tax policy. Consequently, the paper contributes both to the academic and public policy debate.
This paper studies the power of online search intensity metrics, measured by Google, for examining and forecasting exchange rates. We use panel data consisting of quarterly time series from 2004 to 2018 and ten international countries with the highest currency trading volume. Newly, we include various Google search intensity metrics to our panel data. We find that online search improves the overall econometric models and fits. First, four out of ten search variables are robustly significant at one percent and enhance the macroeconomic exchange rate models. Second, country regressions corroborate the panel results, yet the predictive power of search intensity with regard to exchange rates vary by country. Third, we find higher prediction performance for our exchange rate models with search intensity, particularly in regard to the direction of the exchange rate. Overall, our approach reveals a value-added of search intensity in exchange rate models.
This article studies the effects of reverse factoring in a supply chain when the buyer company facilitates its lower short-term borrowing rates to the supplier corporation in return for extended payment terms. We explore the role of interest rate changes, rating changes, and the business cycle position on the cost and benefit trade-off from a supplier perspective. We utilize a combined empirical approach consisting of an event study in Step 1 and a simulation model in Step 2. The event study identifies the quantitative magnitude of central bank decisions and rating changes on the interest rate differential. The simulation computes with a rolling-window methodology the daily cost and benefits of reverse factoring from 2010 to 2018 under the assumption of the efficient market hypothesis. Our major finding is that changes of crucial financial variables such as interest rates, ratings, or news alerts will turn former win-win into win-lose situations for the supplier contingent to the business cycle. Overall, our results exhibit sophisticated trade-offs under reverse factoring and consequently require a careful evaluation in managerial decisions.
This article studies the hidden blemishes of two benchmark rulings of the European Court of Justice (ECJ). In 2015 and 2018, the ECJ approved two unconventional monetary instruments, among others âOutright Monetary Transactionsâ and the âPublic Sector Purchase Programâ. Yet, there is a vigorous debate about both monetary operations in law and economics. In this interdisciplinary article, we address law and economic arguments in order to elucidate insights to the legal community. In particular, we elaborate on the legal implications of a variety of concerning issues such as public policy interference, effect on wealth redistribution, erosion of democratic legitimacy and lack of effectiveness of monetary policy. These topics remain disregarded in the ECJ rulings. Consequently, the verdicts do not identify the economic boundaries of the European Central Bankâs mandate appropriately.
In this paper, we examine the political gridlock in reforming the Economic and Monetary Union. We utilize a twoâstage game with imperfect information in order to study the optimal sequencing. The main results are: first, optimal sequencing requires for incompliant Member States a default option in stageâtwo, which in principle is related to the today's fiscal architecture (EMU-I). Second, we show that compliant countries prefer a reform equilibrium today if and only if they have a free choice about the preferred fiscal architecture at the end â either EMU-II with binding European coordination or EMU-I related to Maastricht. Noteworthy, our sequencing approach works for any design of the EMU-II architecture.
The article studies a novel approach of inflation modeling in economics. We utilize a stochastic differential equation (SDE) of the form dXt=aXtdt+bXtdBtH, where dBtH is a fractional Brownian motion in order to model inflationary dynamics. Standard economic models do not capture the stochastic nature of inflation in the Eurozone. Thus, we develop a new stochastic approach and take into consideration fractional Brownian motions as well as LĂ©vy processes. The benefits of those stochastic processes are the modeling of interdependence and jumps, which is equally confirmed by empirical inflation data. The article defines and introduces the rules for stochastic and fractional processes and elucidates the stochastic simulation output.
Since the global financial crisis of 2008/2009, there has been no challenge to the financial and banking system comparable to that during the Corona crisis.
Weak profitability, unresolved regulatory challenges and increasing competition in the digital sector pose further challenges for banks.
The stability of the financial system and access to financial markets was not at risk during the pandemic. Through joint efforts and better bank capitalisation, the financial system is now more resilient than during the financial crisis.
Provided that grants and loans in the ânext generation EUâ fund are well targeted for structural reforms and investments in the future, this should boost confi-dence and growth.
However, further improvements in financial stability, such as increased capital requirements, regulation of shadow banks or reforms in financial supervision, are needed.
This paper studies the impact of financial liquidity on the macro-economy. We extend a classic macroeconomic modeland compute numerical simulations. The model confirms that persistently low inflation can occur despite a high degreeof financial liquidity due to a reallocation of cash, normal and risk-free bonds. In that regard, our model uncovers anexplanation of a flat Phillips curve. Overall, our approach contributes to a rather disregarded matter in macroeconomictheory.
This paper develops a new methodology in order to study the role of dynamic expectations. Neither reference-point theories nor feedback models are sufficient to describe human expectations in a dynamic market environment. We use an interdisciplinary approach and demonstrate that expectations of non-learning agents are time-invariant and isotropic. On the contrary, learning enhances expectations. We uncover the âyardstick of expectationsâ in order to assess the impact of market developments on expectations. For the first time in the literature, we reveal new insights about the motion of dynamic expectations. Finally, the model is suitable for an AI approach and has major implications on the behaviour of market participants.
This paper studies option pricing based on a reverse engineering (RE) approach. We utilize artificial intelligence in order to numerically compute the prices of options. The data consist of more than 5000 call- and put-options from the German stock market. First, we find that option pricing under reverse engineering obtains a smaller root mean square error to market prices. Second, we show that the reverse engineering model is reliant on training data. In general, the novel idea of reverse engineering is a rewarding direction for future research. It circumvents the limitations of finance theory, among others strong assumptions and numerical approximations under the BlackâScholes model.
The paper studies the reform package proposed by the European Commission on 6 December 2017. First, institutional and economic implications of the reform proposal are analysed. The paper finds that some proposals are beyond the present treaty provisions. For instance, the proposal of a fiscal capacity does not tackle the economic root causes without a supranational transfer mechanism. In fact, the proposed budget neutrality over the medium-term is unfeasible due to cross country heterogeneity in the Eurozone. At the end, the paper develops policy conclusions.
This article investigates the fundamental value of digital platforms, such as Facebook and Google. Despite the transformative nature of digital technologies, it is challenging to value digital services, given that the usage is free of charge. Applying the methodology of discrete choice experiments, we estimated the value of digital free goods. For the first time in the literature, we obtained data for the willingness-to-pay and willingness-to-accept, together with socio-economic variables. The customerÂŽs valuation of free digital services is on average, for Google, 121 ⏠per week and Facebook, 28 âŹ.
This paper studies whether a monetary union can be managed solely by a rule based approach. The Five Presidentsâ Report of the European Union rejects this idea. It suggests a centralisation of powers. We analyse the philosophy of policy rules from the vantage point of the German economic school of thought. There is evidence that a monetary union consisting of sovereign states is well organised by rules, together with the principle of subsidiarity. The root cause of the euro crisis is rather the weak enforcement of rules, compounded by structural problems. Therefore, we suggest a genuine rule-based paradigm for a stable future of the Economic and Monetary Union.
The European Economic and Monetary Union (EMU) has been in turmoil for more than six years. The present governance rules do not seem to solve the problems neither permanently nor effectively. There is no vision about the future of Europe in the 21st century. This article describes a realignment of the economic governance, which does not necessarily lead to a transfer or political union. However, it solves the current and future challenges. In fact, the redesign of present rules is the most likely as well as legally and economically option today. The key ideais the detachment from the compulsive idea of an ever closer union. However, this vision requires boldness towards greater flexibility together with an exit clause or a state insolvency procedure for incompliant member states.