Asylum and migration: A review of Home Office statistics

Asylum applications to the UK have been a headline-grabbing topic. Against a background of much criticism in the media of its handling of the statistics, the Home Office asked the National Audit Office (NAO) in April 2004 to examine the reliability of its quarterly asylum statistics. Alison Langham reports on the NAO's work.     

Choosing between alternative classification criteria to measure the labour force state

Summary.  Labour force counting relies on general guidelines that are set by the International Labour Office to classify individuals into three labour force states: employment, unemployment and inactivity. However, the resulting statistics are known to be sensitive to slight variations in operational definitions which are prima facie consistent with the general guidelines. We consider two interpretations of the general guidelines, operationalized by the criterion that is currently followed by Eurostat and a criterion that was followed by the Italian Statistical Office up to 1992. After showing that the labour force statistics resulting from the two criteria differ considerably, we compare individuals whose classification depends on the criterion that is adopted with individuals whose classification is common between criteria to study the boundary between unemployment and inactivity. An application of our strategy is presented using data from the Italian Labour Force Survey, painting a picture neatly against the criterion that is currently followed by Eurostat.     

Forecasting before,during, and after recession with singular spectrum analysis

The aim of this research is to apply the singular spectrum analysis (SSA) technique, which is a relatively new and powerful technique in time series analysis and forecasting, to forecast the 2008 UK recession, using eight economic time series. These time series were selected as they represent the most important economic indicators in the UK. The ability to understand the underlying structure of these series and to quickly identify turning points such as the on-set of the recent recession is of key interest to users. In recent years, the SSA technique has been further developed and applied to many practical problems. Hence, these series will provide an ideal practical test of the potential benefits from SSA during one of the most challenging periods for econometric analyses of recent years. The results are compared with those obtained using the ARIMA and Holt–Winters models as these methods are currently used as standard forecasting methods in the Office for National Statistics in the UK.     

Modelling the data measurement process for the index of production

Many statistical series that are available from official agencies, such as the Office for National Statistics in the UK and the Bureau of Economic Analysis in the USA, are subject to an extensive process of revision and refinement. This feature of the data is often not explicitly recognized by users even though it may be important to their use of the data. The starting-point of this study is to conceptualize and model the data measurement process as it is relevant to the index of production (IOP). The IOP attracts considerable attention because of its timely publication and importance as an indicator of the UK's industrial base. This study shows that there is one common stochastic trend (and one common factor in terms of observable variables) `driving' 13 vintages of data on the IOP. Necessary and sufficient conditions are derived for the `final' vintage of data on the IOP to be the permanent component of the series in the Gonzalo–Granger sense, and the revisions to be the transitory components. These conditions are not satisfied for the IOP; hence, the per-manent component is a function of all the published vintages.     

No islands: charting a course for UK official statistics

Our system of official statistics in the UK is one of the most decentralised and elaborate in the world. As well as the Office for National Statistics (ONS), it spans several sizeable centres of expertise in Whitehall departments and in the three devolved administrations; and it embraces agencies such as the Higher Education Statistics Agency and the Information Centre for Health and Social Care, which sit at arms length from central departments. In 2008, legislation establishing a new Statistics Board, with oversight not just of the ONS but of all official figures produced by these bodies, will come fully into force. Richard Alldritt of the Statistics Commission and Richard Laux of the ONS identify some of the challenges facing the statistical system at this time of transition and suggests a course that the Statistics Board might want to steer.     

An empirical investigation into the effect of childbearing on economic wellbeing in Europe

This paper investigates the extent childbearing among couples in Europe affects their level of economic well being. We do so by implementing a propensity score matching procedure in combination with a difference-in-difference estimator. Using data from European Community Household Panel Survey (ECHP), we compare how the impact of childbearing on wellbeing varies among countries. We use several measures for wellbeing, including poverty status and various deprivation indices that take into account the multidimensionality of individuals‘ assessment of wellbeing. Not unexpected we find childbearing tend to worsen the economic wellbeing of households, but with important differences in magnitude across countries. In Scandinavian countries the effect is small and rarely significant, it is strong in the UK and also significant in Mediterranean countries. Depending on the measure of wellbeing, we find important differences among countries that are similar in terms of welfare provision.     

Homogeneity test for functional data

In the context of functional data analysis, we propose new sample tests for homogeneity. Based on some well-known depth measures, we construct four different statistics in order to measure distance between the two samples. A simulation study is performed to check the efficiency of the tests when confronted with shape and magnitude perturbation. Finally, we apply these tools to measure the homogeneity in some samples of real data, and we obtain good results using this new method.     

Choice of alpha spending function and time points in clinical trials with one or two interim analyses

One characterization of group sequential methods uses alpha spending functions to allocate the false positive rate throughout a study. We consider and evaluate several such spending functions as well as the time points of the interim analyses at which they apply. In addition, we evaluate the double triangular test as an alternative procedure that allows for early termination of the trial not only due to efficacy differences between treatments, but also due to lack of such differences. We motivate and illustrate our work by reference to the analysis of survival data from a proposed oncology study. Such group sequential procedures with one or two interim analyses are only slightly less powerful than fixed sample trials, but provide for the strong possibility of early stopping. Therefore, in all situations where they can practically be applied, we recommend their routine use in clinical trials. The double triangular test provides a suitable alternative to the group sequential procedures in that they do not provide for early stopping with acceptance of the null hypothesis. Again, there is only a modest loss in power relative to fixed sample tests. Copyright © 2004 John Wiley & Sons, Ltd.     

An alternative view of the 2001 census and future census taking

Summary.  The 2001 census in the UK asked for a return of people 'usually living at this address'. But this phrase is fuzzy and may have led to undercount. In addition, analysis of the sex ratios in the 2001 census of England and Wales points to a sex bias in the adjustments for net undercount—too few males in relation to females. The Office for National Statistics's abandonment of the method of demographic analysis for the population of working ages has allowed these biases to creep in. The paper presents a demographic account to check on the plausibility of census results. The need to revise preliminary estimates of the national population over a period of years following census day—as experienced in North America and now in the UK—calls into question the feasibility of a one-number census. Looking to the future, the environment for taking a reliable census by conventional methods is deteriorating. The UK Government's proposals for a population register open up the possibility of a Nordic-style administrative record census in the longer term.     

Combining census and registration data to estimate detailed elderly migration flows in England and Wales

Summary.  A log-linear model is developed to estimate detailed elderly migration flows by combining data from the 2001 UK census and National Health Services patient register. After showing that the census and National Health Service migration flows can be reasonably combined, elderly migration flows between groupings of local authority districts by age, sex and health status for the 2000–2001 and 2003–2004 periods are estimated and then analysed to show how the patterns have changed. By combining registration data with census data, we can provide recent estimates of detailed elderly migration flows, which can be used for improvements in social planning or policy.     

From Beveridge to Turner: demography, distribution and the future of pensions in the UK

Summary.  The paper outlines the recommendations of the UK Pensions Commission, and the data and analysis on which they were based, including projections of demographic change, trends in private pension saving and evolution of the State pension system. The Commission concluded that, without reform, structural problems with UK pensions would lead to increasingly inadequate and inequitable provision by 2020–2025. It recommended reforms which would lead to a more generous, more universal and less means-tested State system than would otherwise evolve, and the establishment of a low cost national pension savings scheme, into which employees without good employer provision would automatically be enrolled. The proposals, which have now largely been adopted by the UK Government, imply eventual increases both in state spending on pensions as a share of national income and in State pension age, but accompanied by measures to facilitate later and more flexible retirement.     

A note on variable selection in functional regression via random subspace method

Variable selection problem is one of the most important tasks in regression analysis, especially in a high-dimensional setting. In this paper, we study this problem in the context of scalar response functional regression model, which is a linear model with scalar response and functional regressors. The functional model can be represented by certain multiple linear regression model via basis expansions of functional variables. Based on this model and random subspace method of Mielniczuk and Teisseyre (Comput Stat Data Anal 71:725–742, 2014), two simple variable selection procedures for scalar response functional regression model are proposed. The final functional model is selected by using generalized information criteria. Monte Carlo simulation studies conducted and a real data example show very satisfactory performance of new variable selection methods under finite samples. Moreover, they suggest that considered procedures outperform solutions found in the literature in terms of correctly selected model, false discovery rate control and prediction error.     

Bayesian inference for rare errors in populations with unequal unit sizes

We describe a Bayesian model for a scenario in which the population of errors contains many 0s and there is a known covariate. This kind of structure typically occurs in auditing, and we use auditing as the driving application of the method. Our model is based on a categorization of the error population together with a Bayesian nonparametric method of modelling errors within some of the categories. Inference is through simulation. We conclude with an example based on a data set provided by the UK's National Audit Office.     

Precise definitions of some terminology for longitudinal clinical trials: subjects,patient populations,analysis sets,intention to treat,and related terms

Biostatisticians recognize the importance of precise definitions of technical terms in randomized controlled clinical trial (RCCT) protocols, statistical analysis plans, and so on, in part because definitions are a foundation for subsequent actions. Imprecise definitions can be a source of controversies about appropriate statistical methods, interpretation of results, and extrapolations to larger populations. This paper presents precise definitions of some familiar terms and definitions of some new terms, some perhaps controversial. The glossary contains definitions that can be copied into a protocol, statistical analysis plan, or similar document and customized. The definitions were motivated and illustrated in the context of a longitudinal RCCT in which some randomized enrollees are non‐adherent, receive a corrupted treatment, or withdraw prematurely. The definitions can be adapted for use in a much wider set of RCCTs. New terms can be used in place of controversial terms, for example, subject. We define terms specifying a person's progress through RCCT phases and that precisely define the RCCT's phases and milestones. We define terms that distinguish between subsets of an RCCT's enrollees and a much larger patient population. ‘The intention‐to‐treat (ITT) principle’ has multiple interpretations that can be distilled to the definitions of the ‘ITT analysis set of randomized enrollees’. Most differences among interpretations of ‘the’ ITT principle stem from an RCCT's primary objective (mainly efficacy versus effectiveness). Four different ‘authoritative’ definitions of ITT analysis set of randomized enrollees illustrate the variety of interpretations. We propose a separate specification of the analysis set of data that will be used in a specific analysis. Copyright © 2016 John Wiley & Sons, Ltd.     

The effect of school resources on pupil attainment: a multilevel simultaneous equation modelling approach

Summary.  Improving educational achievement in UK schools is a priority, and of particular concern is the low achievement of specific groups, such as those from lower socio-economic backgrounds. An obvious question is whether we should be improving the outcomes of these pupils by spending more on their education. The literature on the effect of educational spending on the achievement of pupils has some methodological difficulties, in particular the endogeneity of school resource levels, and the intraschool correlations in pupils' responses. We adopt a multi-level simultaneous equation modelling approach to assess the effect of school resources on pupil attainment at age 14 years. The paper is the first to apply a simultaneous equation model to estimate the effect of school resources on pupils' achievement, using the newly available national pupil database and pupil level annual school census.     

Dropping out of university: A statistical analysis of the probability of withdrawal for UK university students

From individual level data for an entire cohort of undergraduate students in the 'old' universities in the UK, we use a binomial probit model to estimate the probability that an individual will 'drop out' of university before the completion of their degree course. We examine the cohort of students enrolling full time for a 3- or 4-year degree in the academic year 1989–1990. We find evidence to support both the hypothesis that the completion of courses by students is influenced by the extent of prior academic preparedness and the hypothesis that social integration at university is important. We also find an influence of unemployment in the county of prior residence, especially for poorer male students. Finally, we draw conclusions regarding the public policy of constructing university performance indicators in this area.     

Tests for randomness of observations that involve two factors

Tests for randomness of observations that involve one factor have been considered by many authors among them are Mosteller [4], Bateman [21], Barton and David [1] and Shaughnessy [7]. However, on many occasions, data involve two different factors such as time and location, temperature and pressure, or levels of doses and responses of patients and so on. In this paper, we consider tests for randomness of observations that involve two factors for which data are given in a matrix form. Some new definitions of runs of a matrix of data are defined and discussed. A special kind of run is proposed for the test for randomness. Distributions and properties of this run are studied. Some critical regions are tabulated.     

Functional boxplots based on epigraphs and hypographs

Functional boxplot is an attractive technique to visualize data that come from functions. We propose an alternative to the functional boxplot based on depth measures. Our proposal generalizes the usual construction of the box-plot in one dimension related to the down-upward orderings of the data by considering two intuitive pre-orders in the functional context. These orderings are based on the epigraphs and hypographs of the data that allow a new definition of functional quartiles which is more robust to shape outliers. Simulated and real examples show that this proposal provides a convenient visualization technique with a great potential for analyzing functional data and illustrate its usefulness to detect outliers that other procedures do not detect.