Using the Fraction of Missing Information to Identify Auxiliary Variables for Imputation Procedures via Proxy Pattern‐mixture Models

In many surveys, imputation procedures are used to account for non‐response bias induced by either unit non‐response or item non‐response. Such procedures are optimised (in terms of reducing non‐response bias) when the models include covariates that are highly predictive of both response and outcome variables. To achieve this, we propose a method for selecting sets of covariates used in regression imputation models or to determine imputation cells for one or more outcome variables, using the fraction of missing information (FMI) as obtained via a proxy pattern‐mixture (PMM) model as the key metric. In our variable selection approach, we use the PPM model to obtain a maximum likelihood estimate of the FMI for separate sets of candidate imputation models and look for the point at which changes in the FMI level off and further auxiliary variables do not improve the imputation model. We illustrate our proposed approach using empirical data from the Ohio Medicaid Assessment Survey and from the Service Annual Survey.     

Work incentive and other effects of social assistance and unemployment benefit policy in the Czech Republic

In this paper we provide an account of most of the passive labor market policies (unemployment compensation, social assistance, state social support and the pension system) in the Czech Republic during the 1990–1996 period. The eligibility requirements and benefit levels are described in great detail. Using Labor Force Survey data, we compare the characteristics of unemployed people receiving unemployment benefits with those receiving social assistance and those not receiving any benefits and we find significant differences in their characteristics. Finally, we provide an analysis of the work disincentive effects of the unemployment and social assistance benefits by comparing these benefits to market wages and by analyzing the effect of being in the system on the duration of unemployment of two cohorts of unemployed in 1994 and 1995. We find that social assistance benefits are fairly generous for low income families with more children, individuals with these characteristics have a higher probability of receiving social assistance and they tend to stay unemployed longer than those people with relatively fewer dependants. We conclude that the social assistance scheme seems to be having some disincentive effects for at least one group in the population.     

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Abstract

The Federal Communications Commission relaxed commercial television licensee obligations regarding deceptive advertising in 1985. Local broadcasters may now decide which clearance policies to use to determine if advertisements are deceptive. A national mail survey of commercial television station sales managers was conducted to determine whether advertising clearance policies vary by station profitability or organization size. The proposition that clearance policies may be used to make a station's airtime more attractive to viewers was also given a preliminary test. Results suggest that clearance policies are affected by profitability level and organization size. The implications of study findings are discussed.     

U.S. Citrus Import Demand: Seasonality and Substitution

Citrus fruits make up 1/5 of all fresh fruit consumed in the United States. Given the increasing importance of imported citrus in the diet of American consumers, it is perhaps surprising that no import demand analysis of U.S. citrus has been conducted. Using quarterly U.S. import data for 6 citrus commodities, we employed a demand systems model and evaluated aspects of seasonality. The results suggest wide variations in price responses to different types of imported citrus. The average amplitude and phase shift suggest that all citrus fruits exhibit some seasonality in their imports, likely a result of peak harvesting schedules of exporters.     

The Beliefs Which Influence Young Males to Speed and Strategies to Slow Them Down: Informing the Content of Antispeeding Messages

Young male drivers are overrepresented in road‐related fatalities. Speeding represents a pervasive and significant contributor to road trauma. Antispeeding messages represent a long‐standing strategy aimed at discouraging drivers from speeding. These messages, however, have not always achieved their persuasive objectives that may be due, in part, to them not always targeting the most salient beliefs underpinning the speeding behavior of particular driver groups. The current study elicited key beliefs underpinning speeding behavior as well as strategies used to avoid speeding, using a well‐validated belief‐based model, the theory of planned behavior, and in‐depth qualitative methods. To obtain the most comprehensive understanding about the salient beliefs and strategies of young male drivers, how such beliefs and strategies compared with those of drivers of varying ages and gender, was also explored. Overall, 75 males and females (aged 17–25 or 30–55) participated in group discussions. The findings revealed beliefs that were particularly relevant to young males and that would likely represent key foci for developing message content. For instance, the need to feel in control and the desire to experience positive affect when driving were salient advantages; while infringements were a salient disadvantage and, in particular, the loss of points and the implications associated with potential license loss as opposed to the monetary (fine) loss (behavioral beliefs). For normative influences, young males appeared to hold notable misperceptions (compared with other drivers, such as young females); for instance, young males believed that females/girlfriends were impressed by their speeding. In the case of control beliefs, the findings revealed low perceptions of control with respect to being able to not speed and a belief that something “extraordinary” would need to happen for a young male driver to lose control of their vehicle while speeding. The practical implications of the findings, in terms of providing suggestions for devising the content of antispeeding messages, are discussed.     

Influence of reference points in ex post evaluations of rail infrastructure projects

The paper study the effect of different reference points in time regarding the ‘before’ and ‘after’ situation and how this may influence the ex post evaluation. Four Norwegian railway projects are analysed ex post. We have found that the choice of reference points that are chosen to represent the situation before and after a project, respectively, will often have a major impact on the result of an evaluation. In fact, the studied projects can be presented as either successes or failures, depending on the choice of reference years. The parameters used in this comparison are punctuality, frequency, travel time, and number of travellers. Four projects have been studied. Four parameters for each project generate a total of 16 indicators. By selecting certain years as reference years, 11 of the 16 indicators can be presented as either an increase or decrease. Stakeholders with a biased agenda towards certain projects can actually pick reference years to present the outcome of projects in a way that that fit their agenda. It is recommended that more than one measurement approach is applied in ex post evaluations.