Asymptotic Theory of Outlier Detection Algorithms for Linear Time Series Regression Models

Outlier detection algorithms are intimately connected with robust statistics that down‐weight some observations to zero. We define a number of outlier detection algorithms related to the Huber‐skip and least trimmed squares estimators, including the one‐step Huber‐skip estimator and the forward search. Next, we review a recently developed asymptotic theory of these. Finally, we analyse the gauge, the fraction of wrongly detected outliers, for a number of outlier detection algorithms and establish an asymptotic normal and a Poisson theory for the gauge.     

Oppositional Girlhoods and the Challenge of Relational Politics

Over the last five years, scholars from a wide variety of disciplines have problematized the discourse of “adolescent female exceptionalism” (Switzer in Fem Theory 14(3):345–360, 2013, p. 4) popularized by the NIKE Foundation’s Girl Effect. Arriving at similar conclusions, scholars point to the artificial neocolonial divisions between ‘the West’ and ‘the rest’ of the world animated by an ‘invest in girls’ logic. This paper endeavors to move beyond the “oppositional girlhoods” (Bent in Sociol Stud Child Youth 16(1):3–20, 2013a, p. 7) bind of girl effects discourse to propose that differentially positioned and experienced girlhoods might be better understood as transnational, relational cultural formations. Drawing from our empirical research with girls in North America and Sub-Saharan Africa, we consider the implications of girls’ increasing global visibility as the ‘saviors of humanity’ from different geopolitical contexts. We then go further to suggest the oppositional girlhoods frame assumes reductive, apolitical, and ahistorical claims of divergence between girlhoods in the Global North and Global South “with highly unequal effects” (Gonick et al. in Girlhood Stud 2(3):1–9, 2009, p. 3). By countering the normative construction of global girlhoods as mutually exclusive forms of personhood and historical experience, our project authorizes a new understanding of girlhoods as mutually constituted and relationally contingent. It is from within this relational framework that we propose new directions for thinking about girlhoods transnationally.     

Simulating Properties of the Likelihood Ratio Test for a Unit Root in an Explosive Second-Order Autoregression

This paper provides a means of accurately simulating explosive autoregressive processes and uses this method to analyze the distribution of the likelihood ratio test statistic for an explosive second-order autoregressive process of a unit root. While the standard Dickey-Fuller distribution is known to apply in this case, simulations of statistics in the explosive region are beset by the magnitude of the numbers involved, which cause numerical inaccuracies. This has previously constituted a bar on supporting asymptotic results by means of simulation, and analyzing the finite sample properties of tests in the explosive region.     

Asymptotic Inference on Cointegrating Rank in Partial Systems

The likelihood ratio test for cointegrating rank is analyzed for partial (or conditional) systems in the vector autoregressive error-correction model. Under the assumption of weak exogeneity for the cointegrating parameters, the asymptotic distributions are given and tables of critical values are provided. A discussion is given of some of the assumptions of the model, why they are needed, and how they are tested.     

On the Distribution of Likelihood Ratio Test Statistics for Cointegration Rank

This paper analyses the likelihood ratio test for the hypothesis of reduced cointegration rank in a Gaussian vector autoregressive model. The usual asymptotic distribution typically gives rather large size distortions. This is explained by the fact that the asymptotic distribution of the likelihood ratio test statistic varies across the parameter space. A much improved distribution approximation can be obtained using local asymptotic theory. The idea is discussed for some low dimensional examples.     

Has the Nordic Welfare Model Been Transformed?

The Nordic welfare model is undergoing a fundamental transformation. Using Denmark we show how a universal welfare state model is gradually being transformed into an emergent multi‐tiered welfare state. Whereas the Danish pension system's having become multi‐tiered in the 1990s, with private schemes – collective and individual – supplementing public schemes is well documented, scant attention has focused on more recent developments in other areas of the welfare state. This article shows how the multi‐tiered welfare state spread in the 2000s to policies for families, the unemployed and the sick. Although Denmark still offers universal coverage in core welfare state areas, the increased use of occupational and fiscal welfare as well as changes in public schemes has gradually transformed the nation into a multi‐tiered welfare state that is more dualistic and individualistic, with participation in the labour market becoming still more important for entitlement to benefits. These profound changes have taken place in such a way that although core characteristics are still in place, new structures and understandings of the welfare state are also developing. Thus classical typologies need revision, so that they include more focus on this combination of universality and institutional attachment to the labour market. Moreover, measures of what welfare comprises should include not only public but also private elements.     

Efficient estimation for incomplete multivariate data

We review the Fisher scoring and EM algorithms for incomplete multivariate data from an estimating function point of view, and examine the corresponding quasi-score functions under second-moment assumptions. A bias-corrected REML-type estimator for the covariance matrix is derived, and the Fisher, Godambe and empirical sandwich information matrices are compared. We make a numerical investigation of the two algorithms, and compare with a hybrid algorithm, where Fisher scoring is used for the mean vector and the EM algorithm for the covariance matrix.     

Build-operate-transfer Outsourcing Contracts in Services – Boon or Bane to Emerging Market Vendor Firms?

Build-operate-transfer (BOT) contracting has been widely used in the engineering and construction industry and has recently spread into the service industry domains. Notably, service provider firms from emerging markets, India in particular, are now offering BOT outsourcing contracts in which the client firms are allotted call options, i.e. the right, but not the obligation, to transfer pre-specified assets from the service provider. As such, BOT outsourcing contracts seems to be an interesting contractual novelty that combines the advantages of outsourced and captive offshoring operations. In this paper we investigate under which circumstances a BOT outsourcing contract (i.e. a contract where the client firm exercises its call option) is beneficial, or the opposite, to the emerging market vendor firm. Whether BOT outsourcing contracts are boon or bane to an emerging market vendor basically hinges, we submit, on its internal diffusion of client-specific knowledge and capabilities prior to the execution of the call option.