Local linear kernel estimation for discontinuous nonparametric regression functions

In this paper, we consider using a local linear (LL) smoothing method to estimate a class of discontinuous regression functions. We establish the asymptotic normality of the integrated square error (ISE) of a LL-type estimator and show that the ISE has an asymptotic rate of convergence as good as for smooth functions, and the asymptotic rate of convergence of the ISE of the LL estimator is better than that of the Nadaraya-Watson (NW) and the Gasser-Miiller (GM) estimators.     

On the relational motive for volunteer work

While economists have mainly focused on investment or altruistic motives to explain why people undertake volunteer activities, we rely instead in this paper on the relational motive previously emphasized by social psychologists. Volunteering is seen as a way to build friendly relationships. Drawing on the French survey Vie Associative conducted by INSEE in 2002 on volunteer work and association membership, we shed light on the relevance of this relational motive using two samples of, respectively, 1578 volunteers and 2631 participants in associations. According to their own statements, many volunteers seek to make friends and to meet other people through these activities. Econometric results show that working as a volunteer in an association has a causal impact on the probability of making friends in that association, which also supports the relational motive.     

Werbe-Management in jungen Wachstumsunternehmen

New ventures with above-average growth potential vary significantly with regard to their success and show on average high failure rates which may be traced back to their lack of reputation in the market. This study examines whether systematic advertising planning and control can exert a positive influence on new venture performance and whether these effects vary across life cycle stages. The research model is based upon the contingent resource-based view and has been tested with a sample of 181 new ventures with high growth potential. Findings indicate that, indeed, a large portion of new venture performance can be explained by targeted planning and control methods and tools. As regards advertising control, a moderating effect of life cycle stages emerges: While a negative relationship between advertising control and performance exists in early stages, this relationship becomes significantly positive in later stages.     

THE POWER OF THE LITTLE BLUE PILL: INNOVATIONS AND IMPLICATIONS OF LIFESTYLE DRUGS IN AN AGING POPULATION

The launch of Viagra in April 1998 led to a historically unprecedented high usage of erectile dysfunction (ED) drugs. We test whether Viagra's introduction significantly influenced outcomes for its target population such as sexually transmitted disease (STD) rates of older men, as well as its nontarget populations, such as divorces, natality, the distribution of the age spread within couples, female STDs, and sexual assault rates. We find causal evidence that Viagra's introduction increased gonorrhea rates in older men by 15%–28%. We find no significant evidence of any effects on other variables. We take this as evidence that this lifestyle drug causes significant changes in choices only which affect short‐term outcomes, while long‐term planned decisions are unaffected. Overall, we find that the welfare impacts of Viagra with respect to our outcomes of interest are positive and large. (JEL I1, J1, O33)     

A regression-based approach for estimating primary and secondary particulate matter intake fractions.

One of the common challenges for life cycle impact assessment and risk assessment is the need to estimate the population exposures associated with emissions. The concept of intake fraction (a unitless term representing the fraction of material or its precursor released from a source that is eventually inhaled or ingested) can be used when limited site data are available or the number of sources to model is large. Although studies have estimated intake fractions for some pollutant-source combinations, there is a need to quickly and accurately estimate intake fractions for sources and settings not previously evaluated. It would be expected that limited source or site information could be used to yield intake fraction estimates with reasonable accuracy. To test this theory, we developed regression models to predict intake fractions previously estimated for primary fine particles (PM2.5) and secondary sulfate and nitrate particles from power plants and mobile sources in the United States. Our regression models were able to predict pollutant-specific intake fractions with R2 between 0.53 and 0.86 and equations that reflected expected relationships (e.g., intake fraction increased with population density, stack height influenced the intake fraction of primary but not secondary particles). Further analysis would be needed to generalize beyond this case study and construct models applicable across source categories and settings, but our analysis demonstrates that inclusion of a limited number of parameters can significantly reduce the uncertainty in population-average exposure estimates.     

The concept and measurement of asset poverty: Levels, trends and composition for the U.S., 1983–2001

American prosperity in the second half of the 1980s together with the booming economy of the 1990s created the impression that American households have done well, particularly in terms of wealth acquisition. In this paper, we develop the concept of “asset poverty” as a measure of economic hardship, distinct from and complementary to the more commonly used concept of “income poverty.” We define a household with insufficient assets to enable it to meet basic needs (as measured by the income poverty line) for a period of three months to be asset poor. The results reveal that in the face of the large growth in overall assets in the U.S. and a fall in standard income poverty over the period from 1983 to 2001, the level of asset poverty increased from 22.4 to 24.5 percent. We also find that asset poverty rates for blacks and Hispanics are over twice those for whites; that asset poverty rates fall monotonically with both age and education; that they are much higher for renters than homeowners; and that by family type they range from a low of 5 percent for elderly couples to 71 percent for female single parents.     

Investing in children’s education: are Muslim immigrants different?

Using a unique data set on immigrants living in France in 2003, we investigate whether Muslims invest differently in their children’s education compared to non-Muslims. In particular, we want to assess whether educational inequalities between the children of Muslim and non-Muslim immigrants stem from differences between or within families. After controlling for a broad set of individual and household characteristics, we find no difference in education between children of different religions. However, we do find more within-family inequality in children’s educational achievements among Muslims relative to non-Muslims. The within-family variance is 15 % higher among Muslims relative to Catholics and 45 % higher relative to immigrants with other religions, but the intra-family inequality remains difficult to explain. Overall, our results suggest that Muslim parents tend to redistribute their resources more unequally among their children.     

Premia in Forward Foreign Exchange as Unobserved Components: A Note

We reconsider the signal-extraction approach to measuring premia in the pricing of forward foreign exchange, put forward by Wolff, in which the difference between the forward rate and the associated future spot rate is modeled as an autoregressive moving average (ARMA) model for the risk premium buried in a white-noise forecast error. We point out that an ARMA model for the risk premium is not always identifiable from information on the difference between the forward rate and the future spot rate only. We present solutions to the problem of identification and show how the model for the risk premium can be estimated in a direct way, provided that the identification problem is solved. For reason of comparison, we use the series analyzed by Wolff to estimate the models for risk premia. The results confirm the earlier finding that premia in forward exchange exhibit a certain degree of persistence over time.     

Using focus group interviews to understand staff perceptions from training in the therapeutic community model

The current article is concerned with the use of focus group interviews in understanding staff perceptions of training to work with drug users during the different stages of change from addiction to rehabilitation in the Therapeutic Community model. The article discusses the use of the focus group interview as the most appropriate method for the scope of this study, based on the assumption that trainees are aware of their own needs and demands from training. Methodological issues relevant to the use of focus groups and the individual responses to the training program are discussed. The content and structure of the training program are also discussed. The article concludes that gaining information on people's own perceptions and experiences from the training process can contribute significantly to program improvement.