Frederick J. Zimmerman

Associations of Television Content Type and Obesity in Children

OBJECTIVES We tested the associations of content types of childrens television viewing with subsequent body mass index (BMI) to assess the plausibility of different causal pathways. METHODS We used time-use diary data from the Panel Survey of Income Dynamics to measure television viewing categorized by format and educational and commercial content. Analyses were stratified by age because children younger than 7 years are less able to understand the persuasive intent of advertising. BMI z scores in 2002 were regressed on television viewing, sociodemographic variables, mothers BMI, and BMI in 1997 (for older children only). RESULTS Among children aged 0 to 6 years in 1997, commercial viewing in 1997 was significantly associated with BMI z scores in 2002 in fully adjusted regressions. Among children older than 6 years, commercial viewing in 2002 was associated with 2002 BMI. These results were robust after adjustment for exercise and eating while watching television. CONCLUSIONS The evidence does not support the contention that television viewing contributes to obesity because it is a sedentary activity. Television advertising, rather than viewing per se, is associated with obesity.

Asset smoothing, consumption smoothing and the reproduction of inequality under risk and subsistence constraints

Abstract A growing literature asks whether low-wealth agents can accumulate assets over time or whether they are trapped in poverty. This paper develops a stochastic dynamic programming model with endogenous asset price risk to explore savings and portfolio decisions in a resource-poor environment characterized by risk and subsistence constraints. Optimal portfolio strategies are found to bifurcate, despite divisible assets and fully rational agents. Wealthier agents acquire a higher-yielding portfolio and pursue conventional consumption smoothing. Poorer agents acquire a less remunerative portfolio and pursue asset smoothing, rather than consumption smoothing. Asset-based risk coping thus results in positive correlation between initial wealth and portfolio rate of return.

Associations Between Content Types of Early Media Exposure and Subsequent Attentional Problems

OBJECTIVE. Television and video/DVD viewing among very young children has become both pervasive and heavy. Previous studies have reported an association between early media exposure and problems with attention regulation but did not have data on the content type that children watched. We tested the hypothesis that early television viewing of 3 content types is associated with subsequent attentional problems. The 3 different content types are educational, nonviolent entertainment, and violent entertainment. METHODS. Participants were children in a nationally representative sample collected in 1997 and reassessed in 2002. The analysis was a logistic regression of a high score on a validated parent-reported measure of attentional problems, regressed on early television exposure by content and several important sociodemographic control variables. RESULTS. Viewing of educational television before age 3 was not associated with attentional problems 5 years later. However, viewing of either violent or non-violent entertainment television before age 3 was significantly associated with subsequent attentional problems, and the magnitude of the association was large. Viewing of any content type at ages 4 to 5 was not associated with subsequent problems. CONCLUSIONS. The association between early television viewing and subsequent attentional problems is specific to noneducational viewing and to viewing before age 3.

Teaching by Listening: The Importance of Adult-Child Conversations to Language Development

OBJECTIVE: To test the independent association of adult language input, television viewing, and adult-child conversations on language acquisition among infants and toddlers. METHODS: Two hundred seventy-five families of children aged 2 to 48 months who were representative of the US census were enrolled in a cross-sectional study of the home language environment and child language development (phase 1). Of these, a representative sample of 71 families continued for a longitudinal assessment over 18 months (phase 2). In the cross-sectional sample, language development scores were regressed on adult word count, television viewing, and adult-child conversations, controlling for socioeconomic attributes. In the longitudinal sample, phase 2 language development scores were regressed on phase 1 language development, as well as phase 1 adult word count, television viewing, and adult-child conversations, controlling for socioeconomic attributes. RESULTS: In fully adjusted regressions, the effects of adult word count were significant when included alone but were partially mediated by adult-child conversations. Television viewing when included alone was significant and negative but was fully mediated by the inclusion of adult-child conversations. Adult-child conversations were significant when included alone and retained both significance and magnitude when adult word count and television exposure were included. CONCLUSIONS: Television exposure is not independently associated with child language development when adult-child conversations are controlled. Adult-child conversations are robustly associated with healthy language development. Parents should be encouraged not merely to provide language input to their children through reading or storytelling, but also to engage their children in two-sided conversations.

Audible Television and Decreased Adult Words, Infant Vocalizations, and Conversational Turns: A Population-Based Study

OBJECTIVE To test the hypothesis that audible television is associated with decreased parent and child interactions. DESIGN Prospective, population-based observational study. SETTING Community. PARTICIPANTS Three hundred twenty-nine 2- to 48-month-old children. MAIN EXPOSURES Audible television. Children wore a digital recorder on random days for up to 24 months. A software program incorporating automatic speech-identification technology processed the recorded file to analyze the sounds the children were exposed to and the sounds they made. Conditional linear regression was used to determine the association between audible television and the outcomes of interest. OUTCOME MEASURES Adult word counts, child vocalizations, and child conversational turns. RESULTS Each hour of audible television was associated with significant reductions in age-adjusted z scores for child vocalizations (linear regression coefficient, -0.26; 95% confidence interval [CI], -0.29 to -0.22), vocalization duration (linear regression coefficient, -0.24; 95% CI, -0.27 to -0.20), and conversational turns (linear regression coefficient, -0.22; 95% CI, -0.25 to -0.19). There were also significant reductions in adult female (linear regression coefficient, -636; 95% CI, -812 to -460) and adult male (linear regression coefficient, -134; 95% CI, -263 to -5) word count. CONCLUSIONS Audible television is associated with decreased exposure to discernible human adult speech and decreased child vocalizations. These results may explain the association between infant television exposure and delayed language development.

Violent Television Viewing During Preschool Is Associated With Antisocial Behavior During School Age

OBJECTIVE. The effect of violent television programming on preschoolers’ behaviors is poorly understood. The objective of this study was to test the hypothesis that exposure to violent television viewing when children are 2 to 5 years of age would be associated with antisocial behavior at ages 7 to 10. METHODS. Data were derived from the Panel Study of Income Dynamics. Our primary outcome was being in the 88th percentile of the Behavioral Problem Index antisocial subdomain. Our primary predictor was exposure to violent screen content. RESULTS. Data were available for 184 boys and 146 girls at both time periods. Adjusting for baseline Behavioral Problem Index scores and age, parental education, maternal depression, and cognitive and emotional support, violent television programming was associated with an increased risk for antisocial behavior for boys but not for girls. Neither educational nor nonviolent programming was associated with increased risk for boys or girls. CONCLUSIONS. Viewing of violent programming by preschool boys is associated with subsequent aggressive behavior. Modifying the content that is viewed by young children may be warranted.

The dynamic cost and persistence of asset inequality in an agrarian economy

Abstract A growing literature suggests that asset inequality can be economically costly in the presence of agency costs that constrain labor and capital markets. Unclear in this literature is whether asset markets and optimal individual accumulation of self-finance capacity suffice to eliminate costly inequality over time. This paper uses numerical dynamic programming methods to explore this question with a model of an initially inegalitarian agrarian economy. While an egalitarian asset distribution emerges over time, the process involves sufficiently great productivity losses along the way, that a redistributive policy could improve on the markets performance by both equity and efficiency criteria.

Parental Emotional Support and Subsequent Internalizing and Externalizing Problems Among Children

ABSTRACT. This study examined the association between early emotional support provided by parents and child internalizing and externalizing problems, using a nationally representative, longitudinal sample of 1361 children. Parental emotional support was assessed using the Home Observation for the Measurement of the Environment, incorporating both parent report and interviewer observation. We found that, controlling for child externalizing problems at age 6 years, parental emotional support at age 6 years was negatively related to child externalizing problems at age 8 years. A developmental model that assessed the timing of the emergence of this relationship was then analyzed by including parental emotional support at ages 2, 4, and 6 years as predictors of child externalizing problems at age 8 years. The developmental model suggested that less parental emotional support as early as age 2 years is associated with later externalizing problems in children. This study discusses the importance of very early parental emotional support in promoting positive child development.

Web-based collaborative care for type 1 diabetes: a pilot randomized trial.

BACKGROUND To determine whether a Web-based diabetes case management program based in an electronic medical record can improve glycemic control (primary outcome) and diabetes-specific self-efficacy (secondary outcome) in adults with type 1 diabetes, a pilot randomized controlled trial was conducted. METHODS A 12-month randomized trial tested a Web-based case management program in a diabetes specialty clinic. Patients 21-49 years old with type 1 diabetes receiving multiple daily injections with insulin glargine and rapid-acting analogs who had a recent A1C >7.0% were eligible for inclusion. Participants were randomized to receive either (1) usual care plus the nurse-practitioner-aided Web-based case management program (intervention) or (2) usual clinic care alone (control). We compared patients in the two study arms for changes in A1C and self-efficacy measured with the Diabetes Empowerment Scale. RESULTS A total of 77 patients were recruited from the diabetes clinic and enrolled in the trial. The mean baseline A1C among study participants was 8.0%. We observed a nonsignificant decrease in average A1C (-0.48; 95% confidence interval -1.22 to 0.27; P = 0.160) in the intervention group compared to the usual care group. The intervention group had a significant increase in diabetes-related self-efficacy compared to usual care (group difference of 0.30; 95% confidence interval 0.01 to 0.59; P = 0.04). CONCLUSIONS Use of a Web-based case management program was associated with a beneficial treatment effect on self-efficacy, but change in glycemic control did not reach statistical significance in this trial of patients with moderately poorly controlled type 1 diabetes. Larger studies may be necessary to further clarify the interventions impact on health outcomes.

What explains the relation between family poverty and childhood depressive symptoms

The relation between low socioeconomic status (SES) and depression has been well documented in adult populations. A number of studies suggest that family SES may be associated with depression among children and adolescents as well, although the evidence is mixed. We assessed the relation between family income and depressive symptoms among 457 children aged 11-13 years and examined pathways that may explain this relation. In-person interviews of children and their caregivers were conducted, including assessment of family income and administration of the Computer-based Diagnostic Interview Schedule for Children (C-DISC). Family income was significantly associated with depressive symptoms, with children in the lowest income group (<