IRR computation and the multi-asset problem

The IRR model for individual assets has been the target of serious criticism over the years. The purpose of this paper is to provide a partial rationale for interpreting aggregate firm data based on IRR calculations of individual assets. More specifically, it will be argued that the value of accounting information will be enhanced as a result of depreciation and income recognition schedules being determined by an individual asset's IRR model.     

A first look at the need for enhanced support services for kinship caregivers

This article describes findings from a series of focus groups conducted with formal kinship caregivers in Maryland. The findings reveal that kinship caregivers are committed to providing safety and stability for the children placed with them. The findings also suggest that caregiving can be a significant adjustment for many kinship caregivers and that expanded support services are needed to enhance their relationship with the child welfare agency.     

Field work with the computer: Criteria for assessing systems

Computers, both large and small, can be of great assistance to a field worker. This assistance falls mainly in the area of relieving the field worker from tedious mechanical phases such as typing, sorting, and retrieving information. An examination of field work methods identifies issues and problems which must be addressed by any system for undertaking field work. A rationale for a loose and inclusive (as opposed to an exhaustive and mutually exclusive) coding system is presented. Efficiency, confidentiality, data reduction, and flexibility of testing propositions are discussed as criteria for assessing any system which facilitates field work. The paper concludes by contrasting the methods previously used to collect data, reduce its bulk, code, and retrieve information with what is possible with today's computer hardware and software, and with what will be possible in the near future.We wish to thank Peter Conrad, Susan LeBailly, and the anonymous reviewer of this article for their comments and suggestions.     

A joint-modeling approach to assess the impact of biomarker variability on the risk of developing clinical outcome

In some clinical trials and epidemiologic studies, investigators are interested in knowing whether the variability of a biomarker is independently predictive of clinical outcomes. This question is often addressed via a naïve approach where a sample-based estimate (e.g., standard deviation) is calculated as a surrogate for the “true” variability and then used in regression models as a covariate assumed to be free of measurement error. However, it is well known that the measurement error in covariates causes underestimation of the true association. The issue of underestimation can be substantial when the precision is low because of limited number of measures per subject. The joint analysis of survival data and longitudinal data enables one to account for the measurement error in longitudinal data and has received substantial attention in recent years. In this paper we propose a joint model to assess the predictive effect of biomarker variability. The joint model consists of two linked sub-models, a linear mixed model with patient-specific variance for longitudinal data and a full parametric Weibull distribution for survival data, and the association between two models is induced by a latent Gaussian process. Parameters in the joint model are estimated under Bayesian framework and implemented using Markov chain Monte Carlo (MCMC) methods with WinBUGS software. The method is illustrated in the Ocular Hypertension Treatment Study to assess whether the variability of intraocular pressure is an independent risk of primary open-angle glaucoma. The performance of the method is also assessed by simulation studies.     

Measuring Aspects of Mobility,Polarization and Convergence in the Absence of Cardinality: Indices Based Upon Transitional Typology

Social Indicators Research - Social Mobility, Equality of Opportunity, Polarization, Convergence and Segmentation can each be construed as describing a particular transitional process between...     

The right tool for the job: problems and solutions in visualizing sociological theory

The visualization of social theory is an important part of the development and communication of our theoretical ideas. While most theorists use figures of some kind, few if any have formal training, or guiding rules or principles for the representation of theory. This has often led to poor visualization efforts, and the visual culture of sociology continues to lag behind the natural sciences. The intent of this paper is to serve as a practical and empirically aided guide for social theorists, by providing insights surrounding the cognitive and perceptual properties of certain elements and figures. Through these properties we identify four major problems in theory visualization: vagueness, reduction, unwanted spatial inferences and unwanted metaphorical inferences. We offer solutions to these problems, and to improving theory visualization more generally. Our hope is that this paper will serve as a resource for more thoughtful and informed visualization for practicing social theorists.     

Asthma and allergy as risk factors for suicidal behavior among young adults

An association between allergic disease, depression and suicidality has been reported. Objective: To explore the relationships between suicidality and asthma, allergy, internet addiction, stress, sleep quality, pain/discomfort, and depression, among emerging adults. Participants: 929 college students completed an online survey between October 2015 and April 2017. Methods: A cross-sectional study using multivariate analysis techniques was implemented. Results: Using structural equation modeling, we found that allergies and stress were directly related to pain/discomfort; pain/discomfort was associated to poor sleep, depression, and suicidality. Sleep quality was also affected by stress; while sleep, stress, pain/discomfort, and internet addiction were directly related to depression (all p < .05). Ultimately, four factors impacted suicidality: stress, pain/discomfort, depression, and, indirectly, sleep quality (all p < .05). Although allergy had some effects, these did not reach statistical significance (p < .09). Conclusion: Findings suggest that allergy might impact suicidality indirectly through increased pain/discomfort, poor sleep, and depression.     

Early teen marriage and future poverty

Both early teen marriage and dropping out of high school have historically been associated with a variety of negative outcomes, including higher poverty rates throughout life. Are these negative outcomes due to preexisting differences, or do they represent the causal effect of marriage and schooling choices? To better understand the true personal and societal consequences, in this article, I use an instrumental variables (IV) approach that takes advantage of variation in state laws regulating the age at which individuals are allowed to marry, drop out of school, and begin work. The baseline IV estimate indicates that a woman who marries young is 31 percentage points more likely to live in poverty when she is older. Similarly, a woman who drops out of school is 11 percentage points more likely to be poor. The results are robust to a variety of alternative specifications and estimation methods, including limited information maximum likelihood (LIML) estimation and a control function approach. While grouped ordinary least squares (OLS) estimates for the early teen marriage variable are also large, OLS estimates based on individual-level data are small, consistent with a large amount of measurement error.Historically, individuals were allowed to enter into a marriage contract at a very young age. In Ancient Rome, the appropriate minimum age was regarded as 14 for males and 12 for females. When Rome became Christianized, these age minimums were adopted into the ecclesiastical law of the Catholic Church. This canon law governed most marriages in Western Europe until the Reformation. When England broke away from the Catholic Church, the Anglican Church carried with it the same minimum age requirements for the prospective bride and groom. The minimum age requirements of 12 and 14 were eventually written into English civil law. By default, these provisions became the minimum marriage ages in colonial America. These common laws inherited from the British remained in force in America unless a specific state law was enacted to replace them (see “Marriage Law,” Encyclopædia Britannica 2005; http://www.britannica.com).While Roman, Catholic, English, and early American law may have allowed marriage at 12 for girls and 14 for boys, many questioned the advisability of such early unions. Researchers and policymakers around the turn of the twentieth century recognized that teens may be especially ill-prepared to assume the familial responsibilities and financial pressures associated with marriage.¹ As a result of the changing economic and social landscape of the United States, in the latter part of the nineteenth century and throughout the twentieth century, individual states began to slowly raise the minimum legal age at which individuals were allowed to marry. In the United States, as in most developed countries, age restrictions have been revised upward so that they are now between 15 and 21 years of age.During this same time period, dramatic changes were also occurring in the educational system of the United States (see Goldin 1998, 1999; Goldin and Katz 1997, 2003; Lleras-Muney 2002). Free public schooling at the elementary level spread across the United States in the middle of the nineteenth century, and free secondary schooling proliferated in the early part of the twentieth century. As secondary schooling became more commonplace, states began to pass compulsory schooling laws. States often also passed child labor laws that stipulated minimum age or schooling requirements before a work permit would be granted. These state-specific compulsory schooling and child labor laws are correlated with the legal restrictions on marriage age, indicating that it might be important to consider the impact of all the laws simultaneously.There are at least two rationales often given for the use of state laws as policy instruments to limit teenagers’ choices. The first argument is that teens do not accurately compare short-run benefits versus long-run costs. If teens are making myopic decisions, restrictive state laws could prevent decisions they will later regret. It is also argued that the adverse effects associated with teenagers’ choices impose external costs on the rest of society. If these effects can be prevented, external costs (such as higher welfare expenditures) would also argue for restrictive state laws. Both teenage marriage and dropping out of high school are closely associated with a variety of negative outcomes, including poverty later in life. To assess the relevance of either argument, however, it is important to know whether the observed effects are causal.Any observed negative effects may be due to preexisting differences rather than a causal relationship between teen marriage (or schooling choices) and adverse adult outcomes. Women who marry as teens or drop out of school may come from more disadvantaged backgrounds or possess other unobserved characteristics that would naturally lead to worse outcomes. For example, teens choosing to marry young might have lower unobserved earnings ability, making it hard to draw conclusions about the causal relationship between teenage marriage and poverty.To identify the effect of a teenager’s marriage and schooling choices on future poverty, I use state-specific marriage, schooling, and child labor laws as instruments. Variation in these laws across states and over time can be used to identify the causal impact that teen marriage and high school completion have on future economic well-being. Although compulsory schooling laws have been used as instruments in a variety of settings, this appears to be the first time marriage laws have been used as instruments. The idea of the marriage law instrument is that states with restrictive marriage laws will prevent some teenagers from marrying who would have married young had they lived in a state with more permissive laws.Using the marriage, schooling, and labor laws affecting teens as instruments for early marriage and high school completion, I find strong negative effects for both variables on future poverty status. The baseline instrumental variables (IV) estimates imply that a woman who marries young is 31 percentage points more likely to live in poverty when she is older. Similarly, a woman who drops out of school is 11 percentage points more likely to be living in a family whose income is below the poverty line. The IV results are robust to a variety of alternative specifications and estimation methods, including limited information maximum likelihood (LIML) estimation and a control function approach. In comparison, the ordinary least squares (OLS) estimates are very sensitive to how the data is aggregated, particularly for the early marriage variable. OLS estimates using grouped data are also large, while OLS estimates using individual-level data indicate a small effect for early teen marriage. Auxiliary data indicate a large amount of measurement error in the early marriage variable, suggesting the presence of attenuation bias in the individual-level OLS estimates.The remainder of the article proceeds as follows. I first briefly review the negative outcomes associated with teenage marriage and dropping out of school and discuss alternative perspectives on why teens might make these decisions. The following section describes the data and presents OLS estimates. The next section discusses the early marriage, compulsory schooling, and child labor laws that will be used as instruments. I then present the instrumental variable estimates and conduct several specification and robustness checks, including a discussion of measurement error issues and a reconciliation with the literature on teenage childbearing.