Vector and recurrent singular spectrum analysis: which is better at forecasting?

Singular spectrum analysis (SSA) is an increasingly popular and widely adopted filtering and forecasting technique which is currently exploited in a variety of fields. Given its increasing application and superior performance in comparison to other methods, it is pertinent to study and distinguish between the two forecasting variations of SSA. These are referred to as Vector SSA (SSA-V) and Recurrent SSA (SSA-R). The general notion is that SSA-V is more robust and provides better forecasts than SSA-R. This is especially true when faced with time series which are non-stationary and asymmetric, or affected by unit root problems, outliers or structural breaks. However, currently there exists no empirical evidence for proving the above notions or suggesting that SSA-V is better than SSA-R. In this paper, we evaluate out-of-sample forecasting capabilities of the optimised SSA-V and SSA-R forecasting algorithms via a simulation study and an application to 100 real data sets with varying structures, to provide a statistically reliable answer to the question of which SSA algorithm is best for forecasting at both short and long run horizons based on several important criteria.     

Wavelet analysis of uniformly time-modulated processes

Uniformly time-modulated processes (UTMP) offer a simple, though convenient model for many non stationary time series. However, in many applications, dependency is considered as a disturbing factor. For the UTMP using Weierstrass representation of modulating function, we demonstrated that the correlation between coefficients in wavelet domain is a decreasing function of number of wavelet vanishing moments and tends to zero in progressive rate as we move from finer scales to coarser scales.     

Family Change and Continuity in Iran: Birth Control Use Before First Pregnancy

Using data from the 2002 Iran Fertility Transition Survey, we examined birth control use between marriage and first pregnancy. We focused on the post‐1990 increase in birth control use and develop two explanations. The first posits that birth control use reflects a new marriage form, the conjugal marriage, which places a heightened value on the spousal relationship while deemphasizing the centrality of parenthood. A second explanation stresses the use of a new resource, effective birth control, within an Iranian‐Islamist view of marriage. Key to this explanation is the role of the state—Iranian political/religious actors encourage early marriage and the use of birth control. Although the explanations could be complementary, evidence provides more support for the latter.     

From Acute Palliation to Chronic Care: Using the Narratives of Two Gay Caregivers to Explore Experiences of Providing HIV Support Across Sociohistorical Contexts

Despite the longstanding shift in conceptualizing HIV/AIDS as a site of chronic care, versus one of acute palliation, few attempts have been made to examine caregiving in the context of this change. This study constitutes a preliminary attempt at exploring the evolving nature of HIV/AIDS caregiving among sexual minorities, primarily by comparing the narratives of two partnered caregivers of HIV-positive gay men whose stories are located in disparate sociohistorical contexts. Whereas one caregiver provided support during an era in which HIV/AIDS was primarily conceptualized as acutely life-limiting, the other did so in the contemporary period of chronic HIV care. Although similarities are noted across the stories, distinctions are also apparent in how the caregivers encounter expressions of homophobia and HIV stigma, and negotiate these realities distinctly as a function of sociohistorical context. In particular, despite the salience of these systemic barriers across the two narratives, these expressions of marginalization appear to occur more routinely and indefinitely in the context of chronic care. This article concludes with implications of the study's findings on theory, research, policy, and practice.     

Do Shareholders Really Prefer Their Executives to Maximize the Equity Value? A Newsvendor Case*

In this article, we study how the operational decisions of a firm manager depend on her own incentives, the capital structure, and financial decisions in the context of the newsvendor framework. We establish a relationship between the firm’s cost of raising funds and the riskiness of the inventory decisions of the manager. We consider four types of managers, namely, profit, equity, firm value, and profit‐equity maximizers, and initially assume that they may raise funds to increase the inventory level only by issuing debt. We show that the shareholders are indifferent between the different types of managers when the coefficient of variation (CV) of demand is low. However, this is not the case when the CV of demand is high. Based on the demand and the firm’s specific characteristics such as profitability, leverage, and bankruptcy costs, the shareholders might be better off with the manager whose compensation package is tied to the firm value as opposed to the equity value. We, then, extend our model by allowing the manager to raise the required funds by issuing both debt and equity. For this case we focus on the equity and firm value maximizer managers and show that our earlier results (for the debt only case) still hold subject to the cost of issuing equity. However the benefit of the firm value maximizer manager over the equity maximizer manager for shareholders is considerably less in this case compared to the case where the manager can only issue debt. The Board of Directors can take these factors into consideration when establishing/modifying the right incentive package for the managers. We also incorporate the notion of the asymmetric information to capture its impact on the board of directors’ decision about the managers’ incentive package.     

Race lines and spaces of political action among migrant youth

Recently proposed Anti-Racism Strategy established within a framework of the Australian Government's multicultural policy, People of Australia, identifies ‘youth engagement’ as one of the key areas that needs to be promoted and supported. Young people have been invited to join youth councils and youth forums and work with national, state and local policy-makers. Some have taken up this challenge and became public faces and active members of anti-racism campaigns. Others, however, either remained silent about the discrimination they face, or organised their own grassroots youth-based and youth-led initiatives. This paper discusses individual and collective responses to racism among young people in Australia, focusing on Melbourne, and examines possibilities in which racism, as a common experience among migrant youth, can be utilised to form alternative spaces for political action, challenging not only interpersonal, but also systemic forms of racism. By drawing attention towards institutional and systemic forms of racism, and the historical perpetuation of racist practices, these youth initiatives rely on legal measures, and argue that racism should be discussed in the context of the broader Australian society, not only in relation to minority groups.     

Structural Deficiency or Cultural Racism: The Educational and Social Experiences of Arab‐Australian Youth

This paper discusses the cultural, attitudinal and structural factors that impact upon the social experiences and educational achievements of Arabic‐speaking background (ASB) students in three Melbourne secondary schools with high levels of cultural and linguistic diversity. The paper makes the case for and then outlines a multidimensional approach to multicultural education to better integrate ASB students and their families into the schooling environment. Key strategies developed and tested include a model of school‐community partnership, online and interactive teacher support material (TSM) as well as on‐going teacher professional development workshops on reflexive approaches to cultural diversity and intercultural tension.     

Constructions of Mate Selection Mistakes Among Divorce Applicant Women

This qualitative study aims to explore the patterns and conditions of the wrong decisions women make in choosing their life partners. Grounded theory was employed as the methodological framework. Accordingly, 31 women who had applied for a divorce in the city of Yazd were selected to participate. Purposeful sampling and semistructured interviews were used to select samples and collect data. The findings show wrong decisions in choosing one’s husband were due to heterogeneous partners; emotional, self-willed, and blind decisions; arranged marriages; marriages of convenience; immaturity; conceiving of marriage as an escape from a crisis; dysfunctional parental families; oppressive families; bring destitute; and normative pressure.