The role of numerosity in judgments and decision-making

Linear Biases and Pandemic Communications

BACKGROUND

Previous research has demonstrated a tendency for individuals to mentally linearize nonlinear trends, leading to forecast errors. The present research notes that prior conceptualizations of these linear biases do not make identical predictions and examines how linear biases affect forecasts and risk perceptions of an unfolding epidemic.

METHODS

This research uses an online experiment and a preregistered direct replication in a different online participant pool (total N = 608) to assess the trajectories of forecasts and risk perceptions over time in an unfolding epidemic.

RESULTS

Framing the progress of the epidemic using total cases (v. the rate of new cases) leads to higher forecasts. This research also finds that the effect of frame varies over different time points in the epidemic and differs for forecasts versus risk perceptions. Finally, the effect of frame for forecasted totals is weaker among more numerate individuals.

LIMITATIONS

The studies use repeated measures that occur in 1 session rather than over the course of several months and involve a smooth epidemic curve rather than a noisy one with jagged case counts.

CONCLUSIONS

This research compares prior conceptualizations of linear biases and yields data with implications both for theory on linear biases and for communicators involved in disseminating information about epidemics.

HIGHLIGHTS

Framing the progress of the epidemic using total cases (v. the rate of new cases) leads to higher forecasts.The effect of frame varies over different time points in the epidemic and differs for forecasts v. risk perceptions.The effect of frame for forecasted totals is weaker among more numerate individuals.

Less Is Better: How Nutrition and Low-Carbon Labels Jointly Backfire on the Evaluation of Food Products

(1) Background: Labeling is one of the significant strategies to guide sustainable consumption behaviors. Nowadays, multi labels being displayed on the front-of-pack of food products is a common phenomenon. However, labels seldom operate solo, and competition or complement effects may be exerted on different labels. Therefore, the research objective is to explore the interaction effect when nutrition and low-carbon labels appear simultaneously; (2) Methods: Across four scenario-based experiments, including ice cream, yogurt, steak, and toast, this study manipulated the separate and joint occurrences of low-carbon and nutrition labels, the interaction effect of joint labels was tested, and the serial mediation model, which includes resource allocation and anticipated enjoyment of food consumption, was verified; (3) Results: Results show that people have a positive preference for the nutrition label and the carbon label, respectively, while these two labels working simultaneously attenuate the positive effect of the single label. When facing nutrition and carbon labels simultaneously, people would infer partial resources are allocated to healthy and environmental aspects so they have a lower anticipated enjoyment from food consumption. Thus, these two labels working simultaneously attenuate the positive effect of the single label, and consumers have a lower evaluation of food products. In addition, the joint backfire on the effect is only exerted on people with a higher level of zero-sum bias and only when joint labels have a high consistency of labels; (4) Conclusions: This study solved the contradictory problem of the joint effect of positive labels. The findings in this research contribute to promote sustainable food consumption. We suggest that similar labels should be avoided in the same front-of-pack of food, and manufacturers need to use ads to bring down consumers' zero-sum bias.

Leveraging the Numerosity Effect to Influence Perceived Expensiveness of Virtual Items

Selling virtual items is one of the major revenue sources for online game operators. Therefore, the design of game currency systems is important. This research shows that the game currency exchange rate (e.g., $1 = 1,000 game currency is a higher rate than $1 = 10 game currency) affects price perception of virtual items. When the rate is not prominent in players’ minds (e.g., the rate is not mentioned or players have sufficient game currency in their account), players consider a virtual item as more expensive if the rate is higher. In contrast, when the rate is prominent in players’ minds (e.g., the rate is mentioned and no additional information indicates that players already have sufficient game currency, and thus it is irrelevant), players consider a virtual item as cheaper if the rate is higher. In the latter case, higher rate leads to stronger purchase intention of nonsocial, but not social, virtual items. Our findings show currency system design can affect players’ willingness to spend on virtual items thus affecting the revenue of game operators. Moreover, reminders of the actual monetary value of virtual items might help to reduce players’ overspending driven by the biasing effect of the game currency exchange rate.

Kilo what? Default units increase value sensitivity in joint evaluations of energy efficiency

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.

Numerosity and allocation behavior: Insights using the dictator game

This paper investigates how the numerosity bias influences individuals’ allocation of resources between themselves and others, using the backdrop of the traditional dictator game. Across four studies including both hypothetical and real exchanges of money, we show that the form of the numerical value representing the quantity of the resource (e.g., $20 vs 2000 cents) systematically biases the decision-maker to perceive the quantity s/he is thinking of allocating as being “less than adequate” or “more than adequate”. Essentially, such a biased perception of adequacy with respect to the quantity of the resource consequently influences the decision-maker’s final allocation decision. We attribute this systematic bias to the “numerosity” of the resource. We find that bigger numerical values representing quantity (e.g., 2000 cents) bias decision-makers to over-infer the quantity, thus inducing them to allocate less to the entities they are focusing on.