In ten studies (N = 9187), I systematically investigated the direction and sizeof seven helping effects (the identifiable-victim effect, proportion dominanceeffect, ingroup effect, existence effect, innocence effect, age effect andgender effect). All effects were tested in three decision modes (separateevaluation, joint evaluation and forced choice), and in their weak form (equalefficiency), or strong form (unequal efficiency). Participants read about one,or two, medical help projects and rated the attractiveness of and allocatedresources to the project/projects, or choose which project to implement. Theresults show that the included help-situation attributes vary in their: (1)Evaluability – e.g., rescue proportion is the easiest to evaluate inseparate evaluation. (2) Justifiability – e.g., people prefer to savefewer lives now rather than more lives in the future, but not fewer identifiedlives rather than more statistical lives. (3) Prominence – e.g., peopleexpress a preference to help females, but only when forced to choose.

The unit in which numerical information is presented can have a strong influence on how decision makers evaluate and choose between available choice options. The present work examines the influence of frequently used default units on judgments and decisions of energy efficiency. Across three experiments (Ntotal = 497), our results provide evidence that value sensitivity increases by about 25% in joint evaluation mode when a product attribute is presented in the default unit versus a non-default unit. As a result, presenting an attribute in the default unit led to more favorable evaluations of superior products and less favorable evaluations of inferior products. This result was robust to changes in the numerical magnitude of the non-default unit. Moreover, when joint evaluation was performed across different units, products described using the default unit were evaluated more favorably than products described using a non-default unit. More favorable evaluations based on the default unit translated into a higher willingness to pay for efficiency advantages. We discuss the theoretical and practical implications of default units to guide informed consumer judgments and effective energy efficiency labeling.

People often make predictions about the future based on trends they have observed in the past. Revised probabilistic forecasts can be perceived by the public as indicative of such a trend. In five studies, we describe experts who make probabilistic forecasts of various natural events (effects of climate changes, landslide and earthquake risks) at two points in time. Prognoses that have been upgraded or downgraded from T 1 to T 2 were in all studies expected to be updated further, in the same direction, later on (at T 3). Thus, two prognoses were in these studies enough to define a trend, forming the basis for future projections. This “trend effect” implies that non-experts interpret recent forecast in light of what the expert said in the past, and think, for instance, that a “moderate” landslide risk will cause more worry if it has previously been low than if it has been high. By transcending the experts’ most recent forecasts the receivers are far from conservative, and appear to know more about the experts’ next prognoses than the experts themselves.