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)     

The Strategy‐Focused Factory in Turbulent Times

Few unfocused factories outperform competitors, but focus is elusive because the environment is constantly evolving and this requires changes to a factory's key tasks. So how can focus be achieved and sustained? We present insights derived from an historical analysis of the German Hewlett‐Packard server plant which went through a series of focus changes over the years. Using this example, we provide clues for the right timing of focus changes and discuss critical structural and infrastructural changes required during the focus transitions, as well as cross‐functional coordination and leadership challenges. Our assertion is that production operations constitute a system that can adapt to disruptive change by using the levers of manufacturing policies to stay focused on a limited but absolutely essential task which creates a strategic advantage.     

Assessing Interventions to Reduce the Risk of Campylobacter Prevalence in Broilers

As part of a comprehensive risk assessment on the Campylobacter prevalence in the chicken production chain (from young born chicken till chicken fillet) in the Netherlands, we formulated a quantitative model on the transmission dynamics of Campylobacter at Dutch broiler farms. This model is used to quantify the risk of Campylobacter prevalence in broilers at the time that flocks leave the farm for processing. To this end, we assumed that the Campylobacter prevalence is primarily determined by two parameters, that is, the within- and between-flock transmission. The within-flock transmission was assessed fitting experimental data to a logistic growth model and the between-flock transmission was assessed fitting field data to a generalized linear model (GLM), which included three possible infection routes: (1) via an infected flock in the previous cycle, (2) via other infected flocks present on the farm, and (3) from other sources. This model was applied to assess the efficacy of three control scenarios; (1) a ban on other livestock on broiler farms, (2) a ban on thinning, and (3) a reduction of the between-flock transmission. In contrast to the other scenarios, the third one was shown to be most effective. Theoretically, this is accomplished by improved biosecurity. However, the impact of improved biosecurity cannot be specified into specific control measures, and therefore it is not clear what investments are needed. Finally, we also assessed the efficacy of scheduled treatment, that is, fresh meat production solely from test-negative flocks. We found that the reliability of negative test results, which is crucial, strongly depends on the length of time between testing and slaughter. The sensitivity and specificity of the test appeared to be of minor importance.     

The TTT transformation and a new bathtub distribution model

In this paper we use the total time on test transformation to establish a method for construction of parametric models of lifetime distributions having bathtub-shaped failure rate. We study a particular model which is simple compared to the other existing models. We derive expressions for moments and quantiles and treat estimation methods. Particularly, the maximum likelihood method is studied. Consistency proofs are given.     

Parameter estimation for a special class of Markov chains

The followin paper is dedicated to a special class of stationary Markov chains. The transition probabilities are constructed from bivariate distribution functions of the Morgenstem-Type. These Markov chains are defined by their stationary distribution and a parameter a controlling the correlation between succeeding values of the chain. Relevant properties of the Markov chain are discussed. Some estimations of the parameter a are studied. The maximum likelihood estimator is compared with a simple estimator.     

Unemployment, life satisfaction and retrospective error

Summary.  The paper compares current and 1-year retrospective data on unemployment in the German Socio-Economic Panel study. 13% of all unemployment spells are not reported 1 year later, and another 7% are misreported. The ratio of retrospective to current unemployment has increased in recent years and is related to salience of unemployment measures such as the loss of life satisfaction that is associated with unemployment. Individuals with weak labour force attachment, e.g. women with children or individuals who are close to retirement, have the greatest propensity to under-report unemployment retrospectively. The data are consistent with evidence on retrospective bias found by cognitive psychologists and survey methodologists.     

Leadership and team identification: Exploring the followers' perspective

This study investigates the influence of leadership on followers' identification with their work group. Adopting a qualitative research approach, it takes on the followers' perspective for inductively deriving leadership behaviors that pertain to the development of team identification. Based on in-depth data from members of seven teams in the context of UN peacebuilding operations, four aggregate leadership dimensions can be identified that are conducive to members' team identification: providing guidance, encouraging involvement, role modeling, and administering teamwork. Accordingly, this study adds to the exploration of leadership behaviors relevant for team identification that have not been considered by extant research. The results may lay the foundations for future investigations on complementary effects of different leadership behaviors for fostering followers' identification with their work group.     

Internalization and internationalization under competing real options

The theories of internalization and internationalization provide general factors of international market entry but are not precise about its timing. The theory of real options may complement these approaches as it centers the impact of uncertainty on the timing and dimensioning of investment. A panel study of 5379 German entries to 22 countries suggests that, under the moderating influence of competition, the economic uncertainty in a host country has a U-shaped influence on the moment of entry. The results further reveal that uncertainty has a negative effect on the amount of capital at entry. Uncertainty shows no impact on the share in capital at entry, which challenges the view of international joint ventures as real options.