The solution of time‐dependent population models

We analyze the dynamics of age‐structured population renewal when vital rates make a transition in a finite time interval from arbitrary initial values to any specified final values. The general solution to the renewal equation in such cases is obtained. This solution describes the birth sequence explicitly, and also leads to a general formula for population momentum. We show that the duration of the transition determines the complexity of the solution for the birth sequence. For transitions that are completed in a time smaller than the maximum age of reproduction, we show that the classical Lotka solution found in every textbook also applies, with a small modification, to the time‐dependent case. Our results substantially extend previous work that has often focused on instantaneous transitions or on slow and infinitely persistent change in vital rates.     

The mathematics of sex and marriage,revisited

We analyze the problem of modeling marriages in a two‐sex model of population dynamics. We first deal with the problem of incomplete and inconsistent census data and then use a simulator to compare the performance of a variety of marriage functions in modeling births and couples during the ten‐year period between consecutive U.S. censuses. Unlike most empirical methods for comparing marriage functions based on goodness of fit, the differences in the projections of the various functions in our method are of the same magnitude (or even smaller) than the errors between the projected and real data. We observe that for the population of the United States, the harmonic mean function frequently found and used in the literature is a quite poor performer when compared with many other functions in the family we use.     

‘Autograph of a Nation’: The Daughters of the American Revolution and the National Old Trails Road, 1910–1927

In 1912, a group of women within the National Society of the Daughters of the American Revolution (DAR) undertook to become architects of the first continuous transcontinental automobile route, to be called the ‘National Old Trails Road’ highway. Consistent with many of the private road improvement initiatives during the heyday of America's good roads movement, ‘Daughters’ in many states were involved in mapping the route and posing a variety of marking schemes that would etch upon the landscape the DAR's sponsorship of the route. In doing so, the Daughters staked an explicit claim for the DAR and for American women in the project of nation‐building, by promoting their National Old Trails Road as a culmination of Manifest Destiny. This episode highlights the interrelationship of gender and the nation. This article argues that while women function passively in nationalist rhetoric to symbolise the nation, one must also acknowledge the agency of conservative women's groups in constructing and perpetuating nationalist narratives in ways that were often surprisingly complex and not simply imitative of men.     

Impact of Combat on the Mental Health and Well‐Being of Soldiers and Marines

This presentation introduces a summary of leading edge research and recommendations for a number of changes regarding mental health needs and services for Veterans. Those Veterans who experienced combat exposure and those who have perceived their leadership negatively have greater risks for developing subsequent PTSD. Research data provide support for the use of Battlemind Training as a useful approach to prevent mental health issues at all phases of the deployment cycle. The author also challenges the current use of DSM–IVTR diagnoses with combat Veterans.     

Middle‐Class Political Activism and Middle‐Class Advantage in Relation to Public Services: A Realist Synthesis of the Evidence Base

Since the late 1960s social policy scholarship has been concerned with the distribution of the resources or benefits across social gradients. This article presents a review of the literature on one mechanism by which inequity might be produced – activism by middle‐class service‐users enabling them to capture a disproportionate share of resources. The review used the methodology of realist synthesis to bring together evidence from the UK, the USA and Scandinavian countries over the past 30 years. The aim was to construct a ‘middle‐theory’ to understand how and in which contexts collective and individual activity by middle‐class service‐users might produce inequitable resource allocation or rationing decisions that disproportionately benefit middle‐class service‐users. The article identifies four causal theories which nuance the view that it is the ‘sharp elbows’ of the middle‐classes which confer advantage on this group. It shows how advantage accrues via the interplay between service‐users, providers and the broader policy and social context.     

Lone Parents and Welfare‐to‐Work in England: A Spatial Analysis of Outcomes and Drivers

Mirroring changes across nations of the Organisation for Economic Co‐operation and Development, recent UK governments have redrawn lone parents' entitlement to social assistance benefits ever tighter around participation in the labour market. A radical shift since 2008 has been the gradual transfer of most non‐employed lone parents into the ‘activating’ Jobseekers' Allowance (JSA) regime. The enhanced conditionality requirements of this JSA regime have been justified by both paternalistic and contractualist arguments but, however justified, are built on the premise that behavioural factors drive lone parent employment outcomes, a view made increasingly forcefully under the current Coalition government. This article uses up‐to‐date administrative data at local authority level across England to provide a geographical perspective into the sub‐national changes in lone parent employment outcomes since the transfer to JSA from 2008, as well as the relevant importance of the alternative structural and behavioural accounts to these outcomes. The findings suggest that the JSA transfer has increased lone parent employment, that structural rather than behavioural drivers are more relevant causal factors and that there is good reason to be concerned about the effect of the reforms on the well‐being of lone parents and their children.     

Lone mothers' time allocations: choices and satisfactions

This paper uses the 2006 Australian Time Use Survey to examine the allocation of time to personal care, employment‐related activities, home duties, leisure and child care of lone mothers, in comparison to the time allocations of single women, women in childless couples and partnered mothers. Both primary and secondary time allocations are considered. The satisfactions that women report concerning their current time allocations are also analysed. The time use and satisfaction data are described using both tabulations and multiple regression methods. Lone mothers are shown to have similar time allocations as the other types of households, even though they have different financial and time resources. This raises the concern that lone mothers' desire or need to maintain such time allocations may lead to task overload. Consistent with this, lone mothers are found to be less satisfied with the way they allocate their time than single women and partnered mothers. The tensions associated with time use among lone mothers discussed in the literature are real, and important.     

Bootstrap Determination of the Co‐Integration Rank in Vector Autoregressive Models

This paper discusses a consistent bootstrap implementation of the likelihood ratio (LR) co‐integration rank test and associated sequential rank determination procedure of Johansen (1996). The bootstrap samples are constructed using the restricted parameter estimates of the underlying vector autoregressive (VAR) model that obtain under the reduced rank null hypothesis. A full asymptotic theory is provided that shows that, unlike the bootstrap procedure in Swensen (2006) where a combination of unrestricted and restricted estimates from the VAR model is used, the resulting bootstrap data are I(1) and satisfy the null co‐integration rank, regardless of the true rank. This ensures that the bootstrap LR test is asymptotically correctly sized and that the probability that the bootstrap sequential procedure selects a rank smaller than the true rank converges to zero. Monte Carlo evidence suggests that our bootstrap procedures work very well in practice.     

A Sales Forecast Model for Short‐Life‐Cycle Products: New Releases at Blockbuster

We develop, in this article, a sales model for movie and game products at Blockbuster. The model assumes that there are three sales components: the first is from consumers who have already committed to purchasing (or renting) a product (e.g., based on promotion of, or exposure to, the product prior to its launch); the second comes from consumers who are potential buyers of the product; and the third comes from either a networking effect on closely tied (as in a social group) potential buyers from previous buyers (in the case of movie rental and all retail products) or re‐rents (in the case of game rental). In addition, we explicitly formulate into our model dynamic interactions between these sales components, both within and across sales periods. This important feature is motivated by realism, and it significantly contributes to the accuracy of our model. The model is thoroughly tested against sales data for rental and retail products from Blockbuster. Our empirical results show that the model offers excellent fit to actual sales activity. We also demonstrate that the model is capable of delivering reasonable sales forecasts based solely on environmental data (e.g., theatrical sales, studio, genre, MPAA ratings, etc.) and actual first‐period sales. Accurate sales forecasts can lead to significant cost savings. In particular, it can improve the retail operations at Blockbuster by determining appropriate order quantities of products, which is critical in effective inventory management (i.e., it can reduce the extent of over‐stocking and under‐stocking). While our model is developed specifically for product sales at Blockbuster, we believe that with context‐dependent modifications, our modeling approach could also provide a reasonable basis for the study of sales for other short‐Life‐Cycle products.     

Impacts of off‐farm employment on welfare,food security and poverty: Evidence from rural Vietnam

How off‐farm employment can enhance welfare in terms of food consumption and poverty alleviation is a critical question facing many developing countries. This study addressed that question by pursuing two objectives: (i) to quantify the impact of off‐farm employment on rural households’ welfare, food security and poverty; and (ii) to examine the factors that affect their decision to work off‐farm. Using panel data, we estimated a difference‐in‐difference combined with a propensity score matching model. The findings show that off‐farm employment improves income, ensures food security and contributes to poverty alleviation. The results also show that age, marital status, education, labour, financial capital, land, location, market access and losses from natural disasters are significant contributing factors to the decision to participate in off‐farm employment. The findings suggest that to improve the welfare of rural households, the Vietnamese government should proceed with policies that enhance their opportunities for participation in off‐farm employment.