Bootstrap Statistical Tests of Rank Determination for System Identification

Identification in the context of multivariate state space modelling involves the specification of the dimension of the state vector. One identification approach requires an estimate of the rank of a Hankel matrix. The most frequently used approaches of rank determination rely on information criteria methods. This paper evaluates the performance of some asymptotic tests of rank determination together with their bootstrapped versions against standard information criteria methods. This study is conducted through simulation experiments. Results show that the bootstrapped procedures significantly improve upon the performance of the corresponding asymptotic tests, and are proved better than standard Information Criterion methods.Rank, Bootstrap, Monte Carlo, System identification, Hankel operator

Fiscal spillovers in the Euro area

Copyright @ 2011 Brunel UniversityThis paper analyses the dynamic effects of fiscal imbalances in a given EMU member state on the borrowing costs of other countries in the euro area. The estimation of a multivariate, multi-country time series model (specifically a Global VAR, or GVAR) using quarterly data for the EMU period suggests that euro-denominated government yields are strongly linked with each other. However, financial markets seem to be able to discriminate among different issuers. Consequently, fiscal imbalances in Italy and in other peripheral countries should be closely monitored by their EMU partners and the European institutions

Sectoral money demand models for the euro area based on a common set of determinants

Empirical money demand analysis undertaken at the aggregate level may obscure behavioural differences between the financial, non-financial corporation and household sectors. Looking at the individual and more homogenous sectors may allow more clearly interpretable empirical relationships between money holding, scale variables and opportunity costs to be estimated. Two possible approaches can be taken to address this issue: aggregate and sectoral money holdings are explained either by a common set of determinant variables or by specific determinants, which may differ across sectors. In this analysis, the first approach has been chosen in order to highlight the different elasticities of the long-run money demand with respect to a common set of macroeconomic determinants and thereby to allow comparison of the model for the aggregate M3 with corresponding models for households, non-financial corporations and non-monetary financial intermediaries. This paper presents results for cointegrated VAR systems estimated over a sample of quarterly data from 1991 to 2005. A SUR system is estimated to cross-check the robustness of the findings and to analyse the importance of common shocks across sectors. JEL Classification: E41, C32, E59cointegrated VAR systems, Money demand, sectoral money holdings

Fiscal Spillovers in the Euro Area

This paper analyses the dynamic effects of fiscal imbalances in a given EMU member state on the borrowing costs of other countries in the euro area. The estimation of a multivariate, multi-country time series model (specifically a Global VAR, or GVAR) using quarterly data for the EMU period suggests that euro-denominated government yields are strongly linked with each other. However, financial markets seem to be able to discriminate among different issuers. Consequently, fiscal imbalances in Italy and in other peripheral countries should be closely monitored by their EMU partners and the European institutions.Global VAR methodology, fiscal spillovers, euro area, public debt

Fiscal Spillovers in the Euro Area

This paper analyses the dynamic effects of fiscal imbalances in a given EMU member state on the borrowing costs of other countries in the euro area. The estimation of a multivariate, multi-country time series model (specifically a Global VAR, or GVAR) using quarterly data for the EMU period suggests that euro-denominated government yields are strongly linked with each other. However, financial markets seem to be able to discriminate among different issuers. Consequently, fiscal imbalances in Italy and in other peripheral countries should be closely monitored by their EMU partners and the European institutions.global VAR methodology, fiscal spillovers, euro area, public debt

Harbin: a quantitation PCR analysis tool

Objectives: To enable analysis and comparisons of different relative quantitation experiments, a web-browser application called Harbin was created that uses a quantile-based scoring system for the comparison of samples at different time points and between experiments. Results: Harbin uses the standard curve method for relative quantitation to calculate concentration ratios (CRs). To evaluate if different datasets can be combined the Harbin quantile bootstrap test is proposed. This test is more sensitive in detecting distributional differences between data sets than the Kolmogorov–Smirnov test. The utility of the test is demonstrated in a comparison of three grapevine leafroll associated virus 3 (GLRaV-3) RT-qPCR data sets. Conclusions: The quantile-based scoring system of CRs will enable the monitoring of virus titre or gene expression over different time points and be useful in other genomic applications where the combining of data sets are required

Measuring reproducibility of high-throughput experiments

Reproducibility is essential to reliable scientific discovery in high-throughput experiments. In this work we propose a unified approach to measure the reproducibility of findings identified from replicate experiments and identify putative discoveries using reproducibility. Unlike the usual scalar measures of reproducibility, our approach creates a curve, which quantitatively assesses when the findings are no longer consistent across replicates. Our curve is fitted by a copula mixture model, from which we derive a quantitative reproducibility score, which we call the "irreproducible discovery rate" (IDR) analogous to the FDR. This score can be computed at each set of paired replicate ranks and permits the principled setting of thresholds both for assessing reproducibility and combining replicates. Since our approach permits an arbitrary scale for each replicate, it provides useful descriptive measures in a wide variety of situations to be explored. We study the performance of the algorithm using simulations and give a heuristic analysis of its theoretical properties. We demonstrate the effectiveness of our method in a ChIP-seq experiment.Comment: Published in at http://dx.doi.org/10.1214/11-AOAS466 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org