Jaewon Yoo

Counterfactuals play a pivotal role in the two distinct data science fields of causal inference (CI) and explainable artificial intelligence (XAI). While the core idea behind counterfactuals remains the same in both fields–the examination of what would have happened under different circumstances–there are key differences in how they are used and interpreted. We introduce a formal definition that encompasses the multi-faceted concept of the counterfactual in CI and XAI. We then discuss how counterfactuals are used, evaluated, generated, and operationalized in CI vs. XAI, highlighting conceptual and practical differences. By comparing and contrasting the two, we hope to identify opportunities for cross-fertilization across CI and XAI.

In today's dynamic retail environment, mobile Scan-and-Go services are providing a new way for consumers to shop in-store. To better understand this new retailing practice, we collaborated with a premier book retailer in Asia, which has a well-established mobile Scan-and-Go service. Our findings, based on detailed transactional data, reveal that these users tend to consume a more diverse range of products compared to non-users. More importantly, we show that mobile payment adoption within the context of Scan-and-Go further amplifies the consumption variety of those users. Utilizing a difference-in-differences approach coupled with propensity score matching, we find that mobile payment adoption leads to a significant reduction in the normalized Herfindahl-Hirschman Index (HHI) across multiple dimensions of consumption. This reduction in HHI indicates that users are diversifying their consumption by exploring a broader range of categories. Additionally, we observe a positive impact on overall spending. Grounded in transaction cost theory, our research underscores that the reduction in transaction costs is a key mechanism driving these changes. Our study contributes to the understanding of payment methods and retail technologies, providing novel insights into the strategic use of technological advancements to enhance consumer behavior and bolster emerging sales channels. Our findings offer strategic implications for retailers aiming to leverage technology to thrive in a rapidly evolving market.