{"title":"Robust Inference In Time-Varying Structural VAR Models: The DC-Cholesky Multivariate Stochastic Volatility Model","authors":"Benny Hartwig","doi":"10.2139/ssrn.3466739","DOIUrl":"https://doi.org/10.2139/ssrn.3466739","url":null,"abstract":"This paper investigates how the ordering of variables affects properties of the time-varying covariance matrix in the Cholesky multivariate stochastic volatility model. It establishes that systematically different dynamic restrictions are imposed when the ratio of volatilities is time-varying. Simulations demonstrate that estimated covariance matrices become more divergent when volatility clusters idiosyncratically. It is illustrated that this property is important for empirical applications. Specifically, alternative estimates on the evolution of U.S. systematic monetary policy and inflation-gap persistence indicate that conclusions may critically hinge on a selected ordering of variables. The dynamic correlation Cholesky multivariate stochastic volatility model is proposed as a robust alternative.","PeriodicalId":239853,"journal":{"name":"ERN: Other Econometrics: Econometric & Statistical Methods - Special Topics (Topic)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131555892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Benchmarking Global Optimizers","authors":"Antoine Arnoud, Fatih Guvenen, Tatjana Kleineberg","doi":"10.3386/w26340","DOIUrl":"https://doi.org/10.3386/w26340","url":null,"abstract":"We benchmark seven global optimization algorithms by comparing their performance on challenging multidimensional test functions as well as a method of simulated moments estimation of a panel data model of earnings dynamics. Five of the algorithms are taken from the popular NLopt open-source library: (i) Controlled Random Search with local mutation (CRS), (ii) Improved Stochastic Ranking Evolution Strategy (ISRES), (iii) Multi-Level Single-Linkage (MLSL) algorithm, (iv) Stochastic Global Optimization (StoGo), and (v) Evolutionary Strategy with Cauchy distribution (ESCH). The other two algorithms are versions of TikTak, which is a multistart global optimization algorithm used in some recent economic applications. For completeness, we add three popular local algorithms to the comparison—the Nelder-Mead downhill simplex algorithm, the Derivative-Free Non-linear Least Squares (DFNLS) algorithm, and a popular variant of the Davidon-Fletcher-Powell (DFPMIN) algorithm. To give a detailed comparison of algorithms, we use a set of benchmarking tools recently developed in the applied mathematics literature. We find that the success rate of many optimizers vary dramatically with the characteristics of each problem and the computational budget that is available. Overall, TikTak is the strongest performer on both the math test functions and the economic application. The next-best performing optimizers are StoGo and CRS for the test functions and MLSL for the economic application.","PeriodicalId":239853,"journal":{"name":"ERN: Other Econometrics: Econometric & Statistical Methods - Special Topics (Topic)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114853887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Online Appendix to Accompany 'Parameter Calibration and Rediscovery in the Bates Model'","authors":"Ruixian Huang, Chenghao Li, Yaofei Xu, Yukun Shi","doi":"10.2139/ssrn.3453486","DOIUrl":"https://doi.org/10.2139/ssrn.3453486","url":null,"abstract":"This is an online appendix to accompany the paper 'Parameter Calibration and Rediscovery in the Bates Model'.","PeriodicalId":239853,"journal":{"name":"ERN: Other Econometrics: Econometric & Statistical Methods - Special Topics (Topic)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129063065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Methodological Redirections for an Evolutionary Approach of the External Business Environment","authors":"Charis Vlados, Dimos Chatzinikolaou","doi":"10.5539/jms.v9n2p25","DOIUrl":"https://doi.org/10.5539/jms.v9n2p25","url":null,"abstract":"The usual strategic analysis perceives the external business environment fragmentarily and without a coherent and unifying way. The three levels that a typical analysis of the external business environment involves are a) the macroenvironment and PEST analysis, b) mesoenvironment and “Porter’s diamond”, and c) industrial environment and “Porter’s five forces”. Contrary to the fragmentary analysis of the three levels, this article aims to counter-propose a restructured method of a unified and evolutionary analysis of the external business environment. After presenting the usual analytical handling of the external business environment in the three levels, we suggest that these are rather co-evolving than separate and autonomous spheres of analysis. Therefore, after introducing some elements of the evolutionary socioeconomic theory, we propose a systemic web that perceives the external environment of the socioeconomic organisations in dynamically unified and evolutionary terms. The systemic web conceptualises the approach of the external socioeconomic environment as an open and interactive system comprising three co-evolving spheres in the context of global dynamics: the institutional character of each spatially structured socioeconomic formation; the firm’s functions within the system; and the public-state intervention that contributes to the establishment and reproduction of the system. This conceptual redirection of the methodology of the external business environment can be useful for building an integrated strategic analysis that studies all “micro-meso-macro” components of the entire socioeconomic system.","PeriodicalId":239853,"journal":{"name":"ERN: Other Econometrics: Econometric & Statistical Methods - Special Topics (Topic)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124938255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the Sparsity of Mallows’ Model Averaging Estimator","authors":"Yang Feng, Qingfeng Liu, R. Okui","doi":"10.2139/ssrn.3425424","DOIUrl":"https://doi.org/10.2139/ssrn.3425424","url":null,"abstract":"We show that Mallows' model averaging estimator proposed by Hansen (2007) can be written as a least squares estimation with a weighted <i>L<sub>1</sub></i> penalty and additional constraints. By exploiting this representation, we demonstrate that the weight vector obtained by this model averaging procedure has a sparsity property in the sense that a subset of models receives exactly zero weights. Moreover, this representation allows us to adapt algorithms developed to efficiently solve minimization problems with many parameters and weighted <i>L<sub>1</sub></i> penalty. In particular, we develop a new coordinate-wise descent algorithm for model averaging. Simulation studies show that the new algorithm computes the model averaging estimator much faster and requires less memory than conventional methods when there are many models.","PeriodicalId":239853,"journal":{"name":"ERN: Other Econometrics: Econometric & Statistical Methods - Special Topics (Topic)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129217940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Dissecting Momentum: We Need to Go Deeper","authors":"Dmitry Borisenko","doi":"10.2139/ssrn.3424793","DOIUrl":"https://doi.org/10.2139/ssrn.3424793","url":null,"abstract":"Cross-sectional predictability of returns by past prices, or momentum, is a lasting market anomaly. Previous research reports numerous ways to measure momentum and establishes a multitude of factors predicting its performance. The emerging machine learning asset pricing literature further identifies price-based firm characteristics as major predictors of returns. I investigate predictive power of a broad set of price-based variables over various time horizons in a deep learning framework and document rich non-linear structure in impact of these variables on expected returns in the US equity market. The magnitude and sign of the impact exhibit substantial time variation and are modulated by interaction effects among the variables. The degree of non-linearity in expected returns varies over time and is highest in distressed markets. Incorporating insights from the literature on time-varying, market state-dependent momentum risks and momentum crashes helps to improve out-of-sample performance of neural network portfolios, especially with respect to the downside risk -- investment strategies built on predictions of the deep learning model actively exploit the non-linearities and interaction effects, generating high and statistically significant returns with a robust risk profile and their performance virtually uncorrelated with the established risk factors including momentum. Lastly, I make a case for adoption of automated hyperparameter optimization techniques as an important component of disciplined research in financial machine learning.","PeriodicalId":239853,"journal":{"name":"ERN: Other Econometrics: Econometric & Statistical Methods - Special Topics (Topic)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131237741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Company Valuation as Result of Risk Analysis: Replication Approach as an Alternative to the CAPM","authors":"Werner Gleißner, Dietmar Ernst","doi":"10.2139/ssrn.3458862","DOIUrl":"https://doi.org/10.2139/ssrn.3458862","url":null,"abstract":"Market imperfections call into question the suitability of the CAPM for deriving the cost of capital. The valuation by incomplete replication introduces a valuation concept that takes capital market imperfections into account and derives the risk-adjusted cost of capital (or risk discounts) on the basis of corporate or investment planning and risk analysis. The risk measure is derived consistently (using risk analysis and Monte Carlo simulation) from the cash flows to be valued, that is, the earning risk. Historical stock returns of the valuation object are therefore not necessary. It can be shown that the valuation result of the CAPM can be derived using the approach of imperfect replication as a special case for perfect capital markets.","PeriodicalId":239853,"journal":{"name":"ERN: Other Econometrics: Econometric & Statistical Methods - Special Topics (Topic)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125674621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Investmentstrategien im Rahmen von Übernahmen börsennotierter Gesellschaften – Merger Arbitrage und Maschinelles Lernen (Merger Arbitrage and Machine Learning)","authors":"Frank B. Lehrbaß, Alexander Raasch","doi":"10.2139/ssrn.3454408","DOIUrl":"https://doi.org/10.2139/ssrn.3454408","url":null,"abstract":"<b>German Abstract:</b> Wir stellen verschiedene Investmentstrategien rund um M&A vor. Cash Merger Arbitrage und Stock Merger Arbitrage werden behandelt als auch die Wette auf Compensation Schemes. Zudem untersuchen wir empirisch, ob der Erfolg von M&A mit ökonometrischen Methoden und maschinellem Lernen vorhergesagt werden kann.<br><br><b>English Abstract:</b> We introduce various investment strategies related to M&A situations, explain their risks and returns. Cash Merger Arbitrage and Stock Merger Arbitrage are explored as well as betting on Compensation Schemes. Also, we investigate empirically whether the binary variable success/failure of an attempted M&A deal can be forecasted using classical econometrics and machine learning.","PeriodicalId":239853,"journal":{"name":"ERN: Other Econometrics: Econometric & Statistical Methods - Special Topics (Topic)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121855791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Statistical Tests for Cross-Validation of Kriging Models","authors":"J. Kleijnen, W. V. Beers","doi":"10.2139/ssrn.3395872","DOIUrl":"https://doi.org/10.2139/ssrn.3395872","url":null,"abstract":"Kriging or Gaussian process models are popular metamodels (surrogate models or emulators) of simulation models; these metamodels give predictors for input combinations that are not simulated. To validate these metamodels for computationally expensive simulation models, the analysts often apply computationally efficient cross-validation. In this paper, we derive new statistical tests for so-called leave-one-out cross-validation. Graphically, we present these tests as scatterplots augmented with confidence intervals that use the estimated variances of the Kriging predictors. To estimate the true variances of these predictors, we might use bootstrapping. Like other statistical tests, our tests—with or without bootstrapping—have type I and type II error probabilities; to estimate these probabilities, we use Monte Carlo experiments. We also use such experiments to investigate statistical convergence. To illustrate the application of our tests, we use (i) an example with two inputs and (ii) the popular borehole example with eight inputs. Summary of Contribution: Simulation models are very popular in operations research (OR) and are also known as computer simulations or computer experiments. A popular topic is design and analysis of computer experiments. This paper focuses on Kriging methods and cross-validation methods applied to simulation models; these methods and models are often applied in OR. More specifically, the paper provides the following; (1) the basic variant of a new statistical test for leave-one–out cross-validation; (2) a bootstrap method for the estimation of the true variance of the Kriging predictor; and (3) Monte Carlo experiments for the evaluation of the consistency of the Kriging predictor, the convergence of the Studentized prediction error to the standard normal variable, and the convergence of the expected experimentwise type I error rate to the prespecified nominal value. The new statistical test is illustrated through examples, including the popular borehole model.","PeriodicalId":239853,"journal":{"name":"ERN: Other Econometrics: Econometric & Statistical Methods - Special Topics (Topic)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114253234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Warnings About Future Jumps: Properties of the Exponential Hawkes Model","authors":"Rachele Foschi, Francesca Lilla, C. Mancini","doi":"10.2139/ssrn.3639050","DOIUrl":"https://doi.org/10.2139/ssrn.3639050","url":null,"abstract":"Having observed a cluster of jumps produced by an exponential Hawkes process, we study and quantify the residual length of the cluster. We then formalize the stochastic increasingness property of the durations between two consecutive jumps, which strengthens their positive correlation. Finally we consider the case where the process is only observed discretely and provide bounds for the probability of observing a given number of consecutive jumps.<br><br>As an empirical exercise, we apply our results to a record of JPM's asset prices. First, we show that the identified jumps display dependence and clustering behavior. Second, we find that, under the exponential Hawkes model delivering the best QQ-plot, our formulas indicate a very high probability that an observed cluster of more than 1 jump did not exhaust yet.<br><br>","PeriodicalId":239853,"journal":{"name":"ERN: Other Econometrics: Econometric & Statistical Methods - Special Topics (Topic)","volume":"146 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123333362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}