Distributionally robust L1-estimation in multiple linear regression

Linear regression is one of the most important and widely used techniques in data analysis, for which a key step is the estimation of the unknown parameters. However, it is often carried out under the assumption that the full information of the error distribution is available. This is clearly unrealistic in practice. In this paper, we propose a distributionally robust formulation of L1-estimation (or the least absolute value estimation) problem, where the only knowledge on the error distribution is that it belongs to a well-defined ambiguity set. We then reformulate the estimation problem as a computationally tractable conic optimization problem by using duality theory. Finally, a numerical example is solved as a conic optimization problem to demonstrate the effectiveness of the proposed approach

Do dividends signal future earnings in the Nordic stock markets?

We study the informational content of dividends on three Nordic civil law markets, where other simultaneous but blurring motives for dividends may be weaker. Using aggregate data on real earnings per share and payout ratios, long time series from 1969 to 2010, and methodologies which address problems of endogeneity, non-stationarity and autocorrelation (including a Vector Error Correction Model approach), we find evidence on dividend signaling in Nordic markets. However, we also find heterogeneity in the relationship between dividends and earnings on markets similar in many respects, suggesting that even small variations in the institutional surroundings may be important for the results

Communication within low income families and the management of asthma

This study examines the effects of communication between low income urban parents and children about a chronic disease on the extent to which parent and child effectively manage the illness. Four asthma communication factors were identified by principal component analysis. We found that mothers whose preferred language was Spanish, and families who were not receiving public assistance, communicated more frequently about asthma in general. Spanish speaking mothers and their children communicated more about potential home treatments for asthma, and the more adults in the household the less there was communication about the need for emergency services for asthma. Mothers who preferred to speak Spanish had higher levels of management of the most recent asthma attack. Those whose children communicated with them about asthma in general were higher level managers. Children who influenced their parents' decisions about school attendance, and those whose mothers were more highly educated, had higher levels of asthma attack management. More educated mothers, ones whose children were younger at the time of the onset of asthma, and ones who received public assistance, were more involved "in general" in their child's asthma care.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28643/1/0000458.pd

Indicators of rural youth drug use

The relationships between personal substance use, health beliefs, peer use, sex, and religion were examined using data collected from 265 middle school students in rural northern Michigan and northeastern Wisconsin in January and February 1984. A positive correlation between peer and personal drug use was established. A relationship was also found between health beliefs and personal substance use. In addition, a regression model was able to account for a statistically significant amount of the variance of alcohol, marihuana, and cigarette use in the target population. Recommendations are made concerning future research, methods of improving health education program development, and possible target areas for psychotherapy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45268/1/10964_2005_Article_BF01537674.pd

President Taylor's grand inauguration march /

In bound volumes: Copyright Deposits 1820-186