A Bayesian predictive inference for small area means incorporating covariates and sampling weights

The main goal in small area estimation is to use models to ‘borrow strength’ from the ensemble because the direct estimates of small area parameters are generally unreliable. However, model-based estimates from the small areas do not usually match the value of the single estimate for the large area. Benchmarking is done by applying a constraint, internally or externally, to ensure that the ‘total’ of the small areas matches the ‘grand total’. This is particularly useful because it is difficult to check model assumptions owing to the sparseness of the data. We use a Bayesian nested error regression model, which incorporates unit-level covariates and sampling weights, to develop a method to internally benchmark the finite population means of small areas. We use two examples to illustrate our method. We also perform a simulation study to further assess the properties of our method.     

Effect of autocorrelation when estimating the trend of a time series via penalized least squares with controlled smoothness

This paper studies the effect of autocorrelation on the smoothness of the trend of a univariate time series estimated by means of penalized least squares. An index of smoothness is deduced for the case of a time series represented by a signal-plus-noise model, where the noise follows an autoregressive process of order one. This index is useful for measuring the distortion of the amount of smoothness by incorporating the effect of autocorrelation. Different autocorrelation values are used to appreciate the numerical effect on smoothness for estimated trends of time series with different sample sizes. For comparative purposes, several graphs of two simulated time series are presented, where the estimated trend is compared with and without autocorrelation in the noise. Some findings are as follows, on the one hand, when the autocorrelation is negative (no matter how large) or positive but small, the estimated trend gets very close to the true trend. Even in this case, the estimation is improved by fixing the index of smoothness according to the sample size. On the other hand, when the autocorrelation is positive and large the simulated and estimated trends lie far away from the true trend. This situation is mitigated by fixing an appropriate index of smoothness for the estimated trend in accordance to the sample size at hand. Finally, an empirical example serves to illustrate the use of the smoothness index when estimating the trend of Mexico’s quarterly GDP.     

Developing an interactive approach in social work research: the example of a research study on head injury

Summary The paper examines the processes of a research project aboutthe continuing care needs of head-injured people in order toillustrate an interactive approach in social work research.Influenced by the social work values of empowerment and workingin partnership, the key function of the interactive approachinclude a multidisciplinary research team analysing the researchtopic through different disciplinary perspectives, and selectingresearch methods and dissemination strategies that promote interactiverelationships amongst researchers, respondents and sponsors.Social work practice supplies transferable knowledge, valuesand skills for the interactive approach. The skill of negotiationis used to mitigate unequal distributions of power between researchersand respondents. The paper concludes that the interactive approachis a distinctive characteristic of social work research thatdeserves wider recognition.     

Matching Performance of Continuous Sampling Plans with Single Sampling Plans

Single sampling plans are widely used for appraising incoming product quality. However, for situations where a continuous product flow exists, lot-by-lot demarcations may not exist, and it may be necessary to use alternate procedures, such as CSP-1, for continuous processes. In this case, one would like to be able to understand how average performance of the continuous sampling procedures compares to the more commonly used single sampling plans.

In this study, a model is devised which can be used to relate plan performance between single sample lot acceptance procedures and Dodge's(1943) CSP-1 continuous sampling plan. It is shown that it is generally not possible to match up performance based upon operating characteristic curve expressions for the two plans. Instead, the plans are matched by equating expressions for π(p), the long run proportion of product which is accepted, under both procedures. This is shown to be equivalent to matching up properties on an average outgoing quality basis. The methodology may be extended for any derivative plan under MIL-STD-1235B (1982), the military standard for continuous acceptance sampling.     

ON GENDER GAPS AND SELF‐FULFILLING EXPECTATIONS: ALTERNATIVE IMPLICATIONS OF PAID‐FOR TRAINING

This paper presents a model of self‐fulfilling expectations by firms and households which generates multiplicity of equilibria in pay and housework time allocation for ex‐ante identical spouses. Multiplicity arises from statistical discrimination exerted by firms in the provision of paid‐for training to workers, rather than from incentive problems in the labor market. Employers' beliefs about differences in spouses' reactions to housework shocks lead to symmetric (ungendered) and asymmetric (gendered) equilibria. We find that: (1) the ungendered equilibrium tends to prevail as aggregate productivity in the economy increases (regardless of the generosity of family aid policies), (2) the ungendered equilibrium could yield higher welfare under some scenarios, and (3) gender‐neutral job subsidies are more effective that gender‐targeted ones in removing the gendered equilibrium. (JEL J16, J70, J71)     

Scheduling a multi-stage production system with startup delays

The problem treated is that of multi-stage scheduling as affected by the interdependence of successive stages. An algorithm is developed which incorporates startup delays as analytical functions of cycle times and production rates at adjacent stages. This is accomplished in part by imposing integer multiple restrictions on the relationship between the cycle times at adjacent stages. Total cost is then minimized for a given set of integer multiples.     

Outcomes of a multicomponent physical activity program for sedentary, community-dwelling older adults

This single-group repeated-measures pilot study evaluated the effects of a 10-wk, multicomponent, best-practice exercise program on physical activity, performance of activities of daily living (ADLs), physical performance, and depression in community-dwelling older adults from low-income households (N = 15). Comparison of pretest and posttest scores using a one-tailed paired-samples t test showed improvement (p < .05) for 2 of 3 ADL domains on the Activity Measure-Post Acute Care and for 6 physical-performance measures of the Senior Fitness Test. Repeated-measures ANOVA revealed significant main effects for 3 of 8 physical activity measures using the Yale Physical Activity Scale. Retention rate was 78.9%, and the adherence rate for group sessions was 89.7%. Results suggest that participation in a multicomponent, best-practice physical activity program may positively affect sedentary, community-dwelling older adults' physical activity, ADL performance, and physical performance.