Errors-in-variables regression using estimated latent variables

This note considers a method for estimating regression parameters from the data containing measurement errors using some natural estimates of the unobserved explanatory variables. It is shown that the resulting estimator is consistent not only in the usual linear regression model but also in the probit model and regression models with censoship or truncation. However, it fails to be consistent in nonlinear regression models except for special cases.     

Clinical trial of treatment with saikokaryukotsuboreito for eugonadal patients with late-inset hypogonadism-related symptoms

The purpose of this study was to evaluate the efficacy and safety of saikokaryukotsuboreito (SKRBT), which is widely used for a variety of clinical conditions, neuropsychiatric disorders, for patients with LOH-related symptoms. Twenty-two eugonadal patients over 40 years of age with LOH-related symptoms were included in this study. SKRBT was given orally to these patients three times daily to a total of 7.5 g/day for more than two months. Laboratory and endocrinological profiles were reviewed, and LOH symptoms were judged by means of several health assessment instruments such as the Aging Males' Symptoms (AMS) scale, Self-rated Depression Scale (SDS), International Prostate Symptom Score (IPSS), and King's Health Questionnaire (KHQ). Total AMS scores and AMS subscores were significantly decreased after the treatment. The KHQ, general health perception and impact on life scores were also significantly decreased, although no significant improvement was observed in other KHQ factors or the SDS score or IPSS. The serum concentrations of testosterone fractions did not change with treatment. Laboratory values did not change, and no adverse effects were identified after treatment. We conclude that SKRBT may be considered for treatment of patients with LOH-related symptoms for eugonadal patients.     

Errors-in-variables regression using estimated latent variables

This note considers a method for estimating regression parameters from the data containing measurement errors using some natural estimates of the unobserved explanatory variables. It is shown that the resulting estimator is consistent not only in the usual linear regression model but also in the probit model and regression models with censoship or truncation. However, it fails to be consistent in nonlinear regression models except for special cases.     

Strength-training behavior and perceived environment among Japanese older adults

The authors examined the relationship between strength-training behavior and perceived environment in older Japanese adults. An Internet-based survey was conducted of 293 adults age 68.2 ± 2.8 yr. The dependent variable was regular strength-training behavior. The IPAQ environment module, access to facilities for strength training, and home equipment for strength training were environmental factors. Logistic-regression analysis was employed. After demographic variables (gender, age, educational background, household income, body-mass index, self-rated health status, smoking habit, and residential area) were adjusted for, home equipment for strength training (OR = 2.14, 95% CI = 1.50-3.06), access to facilities for strength training (OR = 2.53, 95% CI = 1.32-4.85), and observing active people (OR = 2.20, 95% CI = 1.06-4.58) were positively correlated with regular strength-training behavior. In conclusion, environmental factors associated with strength-training behavior were access to facilities for strength training, having home equipment for strength training, and observing active people.     

Contrasting effects of urbanization on arboreal and ground-dwelling land snails: role of trophic interactions and habitat fragmentation

Urbanization generally reduces wildlife populations. Individual species responses, however, are often highly variable, and such variability can be explained by differences in species ecological traits. To examine this hypothesis, we focused on two co-occurring land snails, Ezohelix gainesi and Euhadra brandtii sapporo; the former is ground-dwelling and the latter is arboreal. We first estimated their population densities at nine sites distributed along an urbanization gradient: three were located in continuous natural forests, three at the edge of natural forests, and the rest in small isolated forests in urban areas. As a result, the ground-dwelling E. gainesi occurred at highest density in urban forests, followed by forest edges and continuous forests. By contrast, the arboreal E. b. sapporo occurred at highest density in continuous forests, but declined in forest edges and urban forests. We then conducted manipulative field experiments to quantify changes in predation pressure on these species. Ground-tethered E. gainesi and E. b. sapporo were repeatedly predated upon by forest-living mammals in continuous forests, but their survival rates increased in forest edges and urban forests. By contrast, canopy-tethered E. b. sapporo maintained high survival rates in all three forest types. The results indicate that a lack of mammalian predators enables ground-dwelling species to occur at high densities in urban forests, whereas the arboreal species was not affected by this predator relaxation effect. The combination of species-specific behavioural traits and changes in predator communities across an urbanization gradient has important effects on the biodiversity of urban ecosystems.

     

A Study of the Properties of the Item Count Technique

The item count technique is an indirect questioning techniquethat is used to estimate the proportion of people who have engagedin stigmatizing behavior. This technique is expected to yielda more appropriate estimate than the ordinary direct questioningtechnique because it requests respondents to indicate, basedon a list of several items, simply the number of items thatare applicable to them, including the target key item. An experimentalweb survey was conducted in an attempt to compare the directquestioning technique and the item count technique. Comparedwith the direct questioning technique, the item count techniqueyielded higher estimates of the proportion of shoplifters bynearly 10 percentage points, whereas the difference betweenthe estimates using these two techniques was mostly insignificantwith respect to innocuous blood donation. The survey resultssuggest that in the item count technique respondents tend toreport fewer total behaviors compared to the direct questioncase. This tendency is more pronounced in the case of longeritem lists. Three domain estimators for the item count techniquewere compared, and the cross-based method appeared to be themost appropriate method. Large differences in domain estimatesfor shoplifting between the item count and direct questioningtechniques were found among female respondents, middle-agedrespondents, respondents living in urban areas, and highly-educatedrespondents.     

Spouses’ time allocation to pro-environmental activities: who is saving the environment at home?

Family members often perform pro-environmental activities in a cooperative manner. We assume there are two decision-makers in a household, and develop an economic model of pro-environmental activities based on the household production framework. Our theoretical analysis shows how the opportunity cost of time, family structure, and environmental concerns affect an individual’s participation in pro-environmental activities. Using data from the Japanese General Social Survey 2002, we conducted an empirical analysis and found that spouses with lower time costs tended to allocate more time to specific pro-environmental activities. It was further revealed that family structure determines participation in pro-environmental activities.     

Acknowledgment of the Editorial Assistants,Book Review Editors,and Associate Editors

Since the extensive work by Burns and Mitchell, many economists have interpreted economic fluctuations in terms of business-cycle phases. Given this, we argue that, in addition to usual model-selection criteria currently used in the profession, the adequacy of a univariate macroeconomic time series model should be based on its ability to replicate two important business-cycle features of the U.S. data—duration and amplitude. We propose several checks for whether univariate statistical models generate business-cycle features observed in U.S. gross domestic product (GDP) and find that many popular nonlinear models for the log of real GDP are no better at replicating the duration and amplitude features of the data than a simple ARIMA(1, 1, 0).     

Correction to: contrasting effects of urbanization on arboreal and ground-dwelling land snails: role of trophic interactions and habitat fragmentation

Urban Ecosystems - The original version of the article unfortunately contained mistakes in the legends of Fig. 3. The legends (1) Blue square: Euhadra brandtii sapporo, ground is changed...