Parasites often infect genetically diverse host populations, and the evolutionary trajectories of parasite populations may be shaped by levels of host heterogeneity. Mixed genotype host populations, compared to homogeneous host populations, can reduce parasite prevalence and potentially reduce rates of parasite adaptation due to trade-offs associated with adapting to specific host genotypes. Here, we used experimental evolution to select for increased virulence in populations of the bacterial parasite Serratia marcescens exposed to either heterogeneous or homogeneous populations of Caenorhabditis elegans . We found that parasites exposed to heterogeneous host populations evolved significantly less virulence than parasites exposed to homogeneous host populations over several hundred bacterial generations. Thus, host heterogeneity impeded parasite adaptation to host populations. While we detected trade-offs in virulence evolution, parasite adaptation to two specific host genotypes also resulted in modestly increased virulence against the reciprocal host genotypes. These results suggest that parasite adaptation to heterogeneous host populations may be impeded by both trade-offs and a reduction in the efficacy of selection as different host genotypes exert different selective pressures on a parasite population.

For many products, particularly digital content, consumers base purchase-related decisions on not only others’ evaluations (e.g., online reviews) but also their own direct experiences (e.g., previews). Many of them therefore combine “seeing” through their own encounters with “believing” the assessments of others, often being confronted with a situation wherein the former contradicts the latter. This study investigates the dynamics underlying the interactive relationships between online reviews and previews to shed light on how consumers collectively use these pre-buying resources as guidance in purchasing e-books. Our research reveals that consumers wisely leverage previews in accordance with the characteristics of reviews (e.g., volume, valence, and variance). The positive effects of previews increase with decreasing review volume and average valence. Consumers also rely heavily on previews in situations wherein a high variance exists among the indirect evaluations of reviewers. We detect the presence of order effects with respect to exposure to previews and reviews; exposure to previews after accessing reviews more effectively drives sales than when exposure to reviews precedes the encounters. These results provide content providers with useful managerial insights into how they can maximize consumers’ overall prepurchase experiences and enhance content sales through the excellent leveraging of previews and reviews.

While considerable progress has been made in understanding gender mismatch and bias in the physical workplace, there is a limited understanding of how these biases manifest in online platforms where gender masking and manipulation can easily occur. In this study, we collaborate with an online product and service firm in Asia and propose a field experiment design to examine how gender bias influences people‐centric operations in online platforms. By assigning different gender combinations of clients and consultants, we examine how the effect of gender bias differs depending on the gender match or mismatch of the entities in the information exchange process. Using 7 months of data, we provide preliminary evidence of gender biases of different client‐consultant gender pairings. Theoretical and practical implications are discussed.

Prior research on online reviews has taken for granted that consumers submit reviews only after they have fully consumed purchased products or services. Contrastingly, this study uncovered the hidden truth that many book consumers post assessments before, during, and after consumption. Interestingly, many provide numerical review ratings, even with no consumption at all. We also found that review comments formed after incomplete product engagement adversely affect subsequent sales. Consequently, online evaluations crafted on the basis of fragmentary encounters can become a new source of challenges to managers and policymakers who are responsible for preserving the accuracy and informativeness of product critiques. Digital platforms may leverage our findings to improve their design of review systems and policies in ways that enhance the trustworthiness of peer evaluations and correct potential inaccuracies from inadequately informed assessments. For example, managers can revise their review “sorting” structure so that consumers can flexibly reposition text-based reviews in accordance with a consumption index. Managers can likewise take advantage of these study’s insights to effectively re-establish review-posting policies and schemes that encourage consumers to submit reviews after a sufficient amount of products have been consumed.