论我国货币政策传导机制中的障碍

通过对近年来我国出现的通货紧缩现象的分析 ,可以看到中央银行所采取的稳健的货币政策的内容及其执行状况。经济的不景气不是由于货币供应量不足而是在于货币政策的传导机制的不畅。我们应找出传导机制不畅的原因 ,并提出相应的对策     

The Age of Confusion: Why So Many Teens are Getting Pregnant,Turning to Welfare and Ending Up Homeless

The ongoing debate over the flaws in the nation's welfare system centers primarily on two highly charged social ills: teen-age pregnancy and long-term dependence on public assistance. For the poorest and fastest growing segment of the welfare population—homeless mothers—these problems are both severe and inextricably linked. At an alarmingly young age, these women are becoming trapped in a chaotic cycle that offers little structure and few alternatives.     

Friendships in late life: A rural-urban comparison

This study examines the friendship patterns of older adults living in rural and urban areas. The sample consisted of 132 urban adults and 126 rural adults, 65 years of age and older. Respondents were randomly selected and interviewed in their own homes. While both groups were involved in joint social activities and helping behaviors with their friends, there was a distinction in the type of involvement according to geographical location.Karen Roberto is Assistant Professor and Coordinator of the Gerontology Program at the University of Northern Colorado. Her current research interests include women's health issues in aging and older people's involvement with informal support networks. Dr. Roberto holds a Ph.D. in Human Development from Texas Tech University.Jean Pearson Scott is Associate Professor in the Department of Human Development and Family Studies at Texas Tech University. Dr. Scott earned her Ph.D. from the University of North Carolina at Greensboro and is currently conducting research on Alzheimers Disease in the family and the rural elderly.This is a revised version of a paper presented at the Families and Close Relationships: Individuals in Social Interaction Conference, Lubbock, TX, February, 1982.This study was supported by a grant from AARP Andrus Foundation and the Institute for University Research, College of Home Economics, Texas Tech University, Lubbock, Texas 79409.     

BULIMIA: THE TRANSGENERATIONAL VIEW*

Within families presenting with bulimia, there exist interactional patterns that can be said to enable, and perpetuate, the binge-eating and purging symptoms of the identified patient. A transgenerational treatment method is proposed, which not only intervenes in ongoing dysfunctional patterns, but also provides a frame for creating a therapeutic metaphor (“legacy”) to direct the therapy. Rationale and stages of the treatment process are outlined, and a case example is given to illustrate use of the transgenerational frame.     

Partial and inverse autocorrelations in portmanteau-type tests for time series

We present a decomposition of the correlation coefficient between x_t and x_t?k into three terms that include the partial and inverse autocorrelations. The first term accounts for the portion of the autocorrelation that is explained by the inner variables {x_t?1 , x_t?2 , …, x _{t? k+1}}, the second one measures the portion explained by the outer variables {x _t+1, x _t+2, } ∪ {x _t?k?1, x _t?k?2,…} and the third term measures the correlation between x _t and x_t?k given all other variables. These terms, squared and summed, can form the basis of three portmanteau-type tests that are able to detect both deviation from white noise and lack of fit of an entertained model. Quantiles of their asymptotic sample distributions are complicated to derive at an adequate level of accuracy, so they are approximated using the Monte Carlo method. A simulation experiment is carried out to investigate significance levels and power of each test, and compare them to the portmanteau test.     

On sufficient conditions for the strong consistency of least-squares estimates

The strong consistency of the least-squares estimates in regression models is obtained when the errors are i.i.d. with absolute moment of order r, 0<r? 2. The assumptions presented for the random error sequence will permit us to obtain improvements of the conditions on the regressors in order to obtain the strong consistency of the least-squares estimates in linear and nonlinear regression models.     

Strong consistency of least squares estimates with i.i.d. errors with mean values not necessarily defined

We establish strong consistency of the least squares estimates in multiple regression models discarding the usual assumption of the errors having null mean value. Thus, we required them to be i.i.d. with absolute moment of order r, 0<r<2, and null mean value when r>1. Only moderately restrictive conditions are imposed on the model matrix. In our treatment, we use an extension of the Marcinkiewicz–Zygmund strong law to overcome the errors mean value not being defined. In this way, we get a unified treatment for the case of i.i.d. errors extending the results of some previous papers.     

New two-stage sampling designs based on neoteric ranked set sampling

Neoteric ranked set sampling (NRSS) is a recently developed sampling plan, derived from the well-known ranked set sampling (RSS) scheme. It has already been proved that NRSS provides more efficient estimators for population mean and variance compared to RSS and other sampling designs based on ranked sets. In this work, we propose and evaluate the performance of some two-stage sampling designs based on NRSS. Five different sampling schemes are proposed. Through an extensive Monte Carlo simulation study, we verified that all proposed sampling designs outperform RSS, NRSS, and the original double RSS design, producing estimators for the population mean with a lower mean square error. Furthermore, as with NRSS, two-stage NRSS estimators present some bias for asymmetric distributions. We complement the study with a discussion on the relative performance of the proposed estimators. Moreover, an additional simulation based on data of the diameter and height of pine trees is presented.     

A new mixture model on the simplex

This paper is meant to introduce a significant extension of the flexible Dirichlet (FD) distribution, which is a quite tractable special mixture model for compositional data, i.e. data representing vectors of proportions of a whole. The FD model displays several theoretical properties which make it suitable for inference, and fairly easy to handle from a computational viewpoint. However, the rigid type of mixture structure implied by the FD makes it unsuitable to describe many compositional datasets. Furthermore, the FD only allows for negative correlations. The new extended model, by considerably relaxing the strict constraints among clusters entailed by the FD, allows for a more general dependence structure (including positive correlations) and greatly expands its applicative potential. At the same time, it retains, to a large extent, its good properties. EM-type estimation procedures can be developed for this more complex model, including ad hoc reliable initialization methods, which permit to keep the computational issues at a rather uncomplicated level. Accurate evaluation of standard error estimates can be provided as well.     

Soil organic carbon stock in different urban land uses: high stock evidence in urban parks

Urban Ecosystems - Urban areas are major producers of atmospheric CO2 emissions, but at the same time they can offset some of the associated C losses by retaining stable organic carbon in their...