Young Children Fail to use Supply and Demand to Judge the Ease of Obtaining Resources

• In Event: Poster Session 08
  In Poster Session: PS 08 Topic - Cognitive Processes

Abstract

Judgements about supply and demand can guide inferences about the relative difficulty of acquiring resources. For example, they allow us to anticipate that finding a parking spot will be easier where few other drivers are looking for spots than where many other drivers are looking. Such inferences are of basic importance, as they allow us to understand when and where it will be easiest to obtain resources.
We investigated whether young children consider supply and demand when assessing the ease of obtaining resources. Young children, and even infants, understand that physical constraints affect the difficulty of obtaining resources and fulfilling other goals (e.g., Gweon et al., 2017; Liu & Spelke, 2017; Jara-Ettinger et al., 2015). Young children also show an emerging ability to consider supply and demand in judgements about prices and sales (e.g., Berti & Grivet, 1990; Siegler & Thompson, 1998) and the relative desirability of goods (Huh & Friedman, 2019). Using supply and demand to judge the ease of obtaining resources brings together these two sorts of reasoning.
We report the results of four experiments. Our first two experiments provided reason to believe that young children do use supply and demand relations to make judgements of ease and difficulty. In these experiments, 3-year-olds saw stories where groups of characters went to either of two flags to obtain treats. In Experiment 1 (N=60), each flag had a different number of treats (supply), but the same number of characters (demand). In Experiment 2 (N=60), each flag had the same supply, but the demand varied. Overall, children were more likely to choose the high-supply and low-demand sides when judging where obtaining treats would be easier than where this would be harder (manipulated between-subjects), ps≤.002. When asked where obtaining treats would be easier, children mostly indicated the high-supply side, p=.003, but not the low-demand side, p=.178; when asked where this would be harder, they mostly indicated the low-supply and high-demand sides, ps≤.024.
However, rather than using supply and demand relations, children could have succeeded by simply recognizing that the low-supply and high-demand sides did not have enough treats for each character, while the other side did. Our next experiments followed-up on this issue. In Experiment 3, 3-year-olds (N=60) saw stories where each flag had enough treats for the characters, and then judged where obtaining treats would be easier. We found a marginal effect of condition, p=.053. However, children performed worse than chance in the different-demand condition, p=.027, and performed at chance in the different-supply condition, p=.592; see Figure 1. Given this poor performance, Experiment 4 included older children. We tested 3-6-year-olds (N=66) in a within-subjects design, where children again judged where obtaining treats would be easier. However, children’s responses did not vary across different-demand and different-supply conditions, p=.640, with age, p=.414, and there was no interaction, p=.914.
Together, our findings suggest that young children fail to use supply and demand to judge the ease of obtaining resources. However, they may infer ease by recognizing when there aren’t enough treats for all competitors.

Authors

• Emily Elizabeth Stonehouse, University of Waterloo
  Presenting Author

• Michelle Huh, University of Waterloo
  Non-Presenting Author

• Ori Friedman, University of Waterloo
  Non-Presenting Author