CONTEXT Early age at first sex has been identified as a risk factor for unplanned pregnancy and HIV infection. However, the emotional relationships and physical behaviors that precede first intercourse, and how they differ by sex, also may provide important cues about how to prevent sexual risk behavior. METHODS The precoital activities of 2,051 adolescents aged 17-19 in Cebu, Philippines, ar...

The genesis of new statistical models has rarely been within the field of marketing research. Marketing researchers have mainly borrowed from other fields. Conjoint analysis and the more recent discrete choice or choice-based conjoint methods are no exception. Conjoint methods were based on work in the sixties by mathematical psychologists and statisticians Luce and Tukey (1964), and discrete c...

A growing body of empirical literature uses structurally-derived economic models to study the nature of competition and to measure explicitly the economic impact of strategic policies. While several approaches have been proposed, the discrete choice demand system has experienced wide usage. The heterogeneous, or ‘‘mixed’’, logit in particular has been widely applied due to its parsimonious stru...

Customers often compare and evaluate alternative products before making purchase decisions. Understanding customer preference is an important step for choice modeling in engineering design. This study presents a network approach to model co-consideration relations between products in supporting engineering design decisions. The network approach of co-consideration represents each product as a n...

We reconsider the problem of producing fair and accurate tariffs based on aggregated insurance data giving numbers of claims and total costs for the claims. Jorgensen and de Souza (Scand. Actuarial J., 1994) assumed Poisson arrival of claims and gamma distributed costs for individual claims. Jorgensen and de Souza (1994) directly modelled the risk or expected cost of claims per insured unit, p ...

Individuals' decisions and behaviour can play a critical role in determining both the probability and severity of injury. Behavioural decision research studies peoples' decision-making processes in terms comparable to scientific models of optimal choices, providing a basis for focusing interventions on the most critical opportunities to reduce risks. That research often seeks to identify the 'm...

Rational choice of teenage sexual behaviour lead to radically different predictions than do models that assume such behaviour is random. Existing empirical evidence has not been able to distinguish conclusively between these competing models. Using regional data from England between 1998 and 2001, I find that recent increases in availability of youth family planning clinics are associated with ...

This paper presents a method for inferring the distribution of voter ideal points on a single dimension from individual-level binary choice data. The statistical model and estimation technique draw heavily on the psychometric literature on test taking and, in particular, on the work of Bock and Aitkin (1981) and are similar to several recent methods of estimating legislative ideal points (Londr...

BACKGROUND A discrete choice experiment (DCE) is a preference survey which asks participants to make a choice among product portfolios comparing the key product characteristics by performing several choice tasks. Analyzing DCE data needs to account for within-participant correlation because choices from the same participant are likely to be similar. In this study, we empirically compared some c...

A major component of the Affordable Care Act involves the expansion of state Medicaid programs to cover the uninsured poor. In the wake of the 2012 Supreme Court decision upholding and modifying reform legislation, states can decide whether to expand Medicaid-and twenty states are still not proceeding as of August 2015. What explains state choices about participation in expansion, including gov...