In the current paper we investigate how feedback over decision outcomes may affect future decisions. In an experimental study we demonstrate that if people receive feedback over the outcomes they obtained (“factual outcomes”) and the outcomes they would have obtained had they decided differently (“counterfactual outcomes”), they become regret-averse in subsequent decisions. This effect is not only observed when this feedback evoked regret (with counterfactual outcomes being higher than factual outcomes), but even when the feedback evoked no regret (with factual outcomes being equal to counterfactual outcomes). The findings suggest that this effect on subsequent decisions is at least partly due to the transfer of a comparison mind-set triggered in the prior choice.

The sunk cost fallacy is the tendency to continue an endeavour once an investment in money, effort, or time has been made. We studied how people’s chronic orientation to cope with failing projects (i.e., action vs. state orientation) influences the occurrence of this sunk cost effect. We found that people with a state orientation, who have a tendency to ruminate about past events and have a hard time to let go of them, were especially prone to fall in the sunk cost trap. People with an action orientation, who more easily let go of past events, were not susceptible to the sunk cost effect. We discuss the implications of these results for the sunk cost fallacy literature.

Research has identified loss aversion as a strong and robust phenomenon, but has also revealed some moderators affecting the magnitude of its effect on decision making. In the current article, we draw attention to the fact that even the measurement of loss aversion itself may affect its magnitude by inducing a focus on either losses or gains. In three studies, we provide empirical evidence for such a measurement-induced focus. In all studies we used coin-toss gambles—in which there is a 50/50 chance to win or to lose—to assess gain/loss ratios as a measure of loss aversion. Participants either filled out the loss side or the gain side of this gain/loss ratio. The studies consistently showed that—using within- and between-subject designs and anticipated and real coin-toss gambles—the strength of loss aversion depended on the measurement format (fill-in-the-loss versus fill-in-the-gain); filling in the loss side increased loss aversion. Moreover, loss aversion was more affected by the stakes of the gamble in the fill-in-the-loss format than in the fill-in-the-gain format.

Helminth infections have large negative impacts on production efficiency in ruminant farming systems worldwide, and their effective management is essential if livestock production is to increase to meet future human needs for dietary protein. The control of helminths relies heavily on routine use of chemotherapeutics, but this approach is unsustainable as resistance to anthelmintic drugs is widespread and increasing. At the same time, infection patterns are being altered by changes in climate, land-use and farming practices. Future farms will need to adopt more efficient, robust and sustainable control methods, integrating ongoing scientific advances. Here, we present a vision of helminth control in farmed ruminants by 2030, bringing to bear progress in: (1) diagnostic tools, (2) innovative control approaches based on vaccines and selective breeding, (3) anthelmintics, by sustainable use of existing products and potentially new compounds, and (4) rational integration of future control practices. In this review, we identify the technical advances that we believe will place new tools in the hands of animal health decision makers in 2030, to enhance their options for control and allow them to achieve a more integrated and sustainable approach to helminth control in support of animal welfare and production.

Mismatch in the phenology of trophically linked species as a result of climate warming has been shown to have far-reaching effects on animal communities, but implications for disease have so far received limited attention. This paper presents evidence suggestive of phenological asynchrony in a host-parasite system arising from climate change, with impacts on transmission. Diagnostic laboratory data on outbreaks of infection with the pathogenic nematode Nematodirus battus in sheep flocks in the UK were used to validate region-specific models of the effect of spring temperature on parasite transmission. The hatching of parasite eggs to produce infective larvae is driven by temperature, while the availability of susceptible hosts depends on lambing date, which is relatively insensitive to inter-annual variation in spring temperature. In southern areas and in warmer years, earlier emergence of infective larvae in spring was predicted, with decline through mortality before peak availability of susceptible lambs. Data confirmed model predictions, with fewer outbreaks recorded in those years and regions. Overlap between larval peaks and lamb availability was not reduced in northern areas, which experienced no decreases in the number of reported outbreaks. Results suggest that phenological asynchrony arising from climate warming may affect parasite transmission, with non-linear but predictable impacts on disease burden. Improved understanding of complex responses of host-parasite systems to climate change can contribute to effective adaptation of parasite control strategies.

In the current paper we present an instrumental approach to deception. This approach incorporates the notion that bargainers (a) will use deception as a means to reach their goals in bargaining but (b) will refrain from using deception when they have alternative means to reach their goals. We demonstrate that different goals can lead to differences in the use of deception (Experiment 1). Furthermore, we demonstrate that reactions to deceit can also be understood from an instrumental perspective (Experiment 2).

Unfair offers in bargaining may have disruptive effects because they may reduce interpersonal trust. In such situations future trust may be strongly affected by social accounts (i.e., apologies vs. denials). In the current paper we investigate when people are most likely to demand social accounts for the unfair offer (Experiment 1), and when social accounts will have the highest impact (Experiment 2). We hypothesized that the need for and impact of social accounts will be highest when the intentions of the other party are uncertain. The results provided support for this reasoning.

We study a queueing system with a finite number of input sources. Jobs are individually generated by a source but wait to be served in batches, during which the input of that source is stopped. The service speed of a server depends on the mode of other sources and thus includes interdependencies. The input and service times are allowed to be generally distributed. A classical example is a machine repair system where the machines are subject to shocks causing cumulative damage. A product-form expression is obtained for the steady state joint queue length distribution and shown to be insensitive (i.e. to depend on only mean input and service times). The result is of both practical and theoretical interest as an extension of more standard batch service systems.