The diffusion of a new product, whose price is expected to fall progressively, is modelled as a sequence of Wars of Attrition. The likely pattern of diffusion is found to be reasonably consistent with the empirically observed S-shape.

This paper summarizes the major findings from a nonresponse bias analysis of the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 (ECLS-K) first grade data. The analysis examines the potential for bias in estimates from the ECLS-K due to attrition (nonresponse) between the base year (rounds 1 and 2) and first grade (rounds 3 and 4). This work builds on a base year nonresponse b...

Using a randomized experiment, this study investigates the impact of sustained investment in parenting, from pregnancy until age five, in the context of extensive welfare provision. Providing the Preparing for Life program, incorporating home visiting, group parenting, and baby massage, to disadvantaged Irish families raises children’s cognitive and socio-emotional/behavioral scores by two-thir...

This article analyzes generalized method of moments estimation when the sample is not a random draw from the population of interest. Auxiliary information, in the form of moments from the population of interest, is exploited to compute weights that are proportional to the inverse probability of selection. The essential idea is to construct weights for each observation in the primary data such t...