The impact of online reviews on consumer evaluations and decision making: an analysis of review volume and user-generated photos

This thesis investigates the impact of online social influence on consumer behaviour, specifically within the context of online reviews. It examines how review volume and user-generated photos affect consumer evaluations and decision-making. In Chapter 2, I introduce a novel phenomenon, the N-effect, which explores how opinion volume influences the content of online evaluations. I find that as the number of opinions increases, the content becomes more emotional and less analytical. In Chapter 3, I investigate the role of user-generated photos in shaping purchase intentions. This research demonstrates that photos can enhance review helpfulness, even when they lack diagnostic information. This effect is driven by the confidence signalled by the reviewer when posting a review with a photo, which is later assimilated by readers, leading to increased perceived helpfulness and purchase likelihood. This thesis makes several theoretical and practical contributions to the literature on human interaction with technology. Theoretically, it expands our understanding of online social influence by examining the dynamics of online opinion expression and content. I contribute to the literature on group size by demonstrating how responsibility may be lost in online contexts. Furthermore, the findings provide insights into the social influence of photos on viewers and the role of pseudo-evidence in shaping beliefs and attitudes. From a practical standpoint, this research offers valuable insights for online platform managers and marketers on interpreting and using consumer-written reviews. Overall, this thesis contributes to the existing literature on online social influence and provides insights for businesses to improve communication and interpretation with consumers by better understanding and leveraging online reviews and opinions.Open Acces

Online reputation management: estimating the impact of management responses on consumer reviews

We investigate the relationship between a firm’s use of management responses and its online reputation. We focus on the hotel industry and present several findings. First, hotels are likely to start responding following a negative shock to their ratings. Second, hotels respond to positive, negative, and neutral reviews at roughly the same rate. Third, by exploiting variation in the rate with which hotels respond on different review platforms and variation in the likelihood with which consumers are exposed to management responses, we find a 0.12-star increase in ratings and a 12% increase in review volume for responding hotels. Interestingly, when hotels start responding, they receive fewer but longer negative reviews. To explain this finding, we argue that unsatisfied consumers become less likely to leave short indefensible reviews when hotels are likely to scrutinize them. Our results highlight an interesting trade-off for managers considering responding: fewer negative ratings at the cost of longer and more detailed negative feedback.Accepted manuscrip

Does Amazon Scare Off Customers? The Effect of Negative Spotlight Reviews on Purchase Intention

Online retailers provide review systems to consumers in order to improve perceived trustworthiness and boost sales. We examine the effects of review valence and valence intensity on consumer purchase intention. Review adoption emerges as a novel, important moderating variable. We find that positive reviews have a stronger effect on consumer purchase intention than negative reviews. Moderate reviews always lead to higher purchase intention than extreme reviews, but the size of the effect is greater for extremely negative reviews than moderately negative reviews. The effect is reversed for positive reviews. Our results imply that a recent innovation in Amazon’s review system, highlighting negative reviews along with positive spotlight reviews, must be designed carefully to avoid losing customers. Choosing the wrong combination of reviews can diminish the positive effect of spotlight reviews on sales by nearly 20%

Review Manipulation: Literature Review, and Future Research Agenda

Background: The phenomenon of review manipulation and fake reviews has gained Information Systems (IS) scholars’ attention during recent years. Scholarly research in this domain has delved into the causes and consequences of review manipulation. However, we find that the findings are diverse, and the studies do not portray a systematic approach. This study synthesizes the findings from a multidisciplinary perspective and presents an integrated framework to understand the mechanism of review manipulation. Method: The study reviews 88 relevant articles on review manipulation spanning a decade and a half. We adopted an iterative coding approach to synthesizing the literature on concepts and categorized them independently into potential themes. Results: We present an integrated framework that shows the linkages between the different themes, namely, the prevalence of manipulation, impact of manipulation, conditions and choice for manipulation decision, characteristics of fake reviews, models for detecting spam reviews, and strategies to deal with manipulation. We also present the characteristics of review manipulation and cover both operational and conceptual issues associated with the research on this topic. Conclusions: Insights from the study will guide future research on review manipulation and fake reviews. The study presents a holistic view of the phenomenon of review manipulation. It informs various online platforms to address fake reviews towards building a healthy and sustainable environment

Structural market changes and strategic adaptation along the value chain:theoretical perspectives and empirical evidence

Strukturelle Veränderungen der Wettbewerbslandschaft, insbesondere die Deregulierung von Märkten und der rasante technologische Fortschritt, nehmen Einfluss auf die optimale Gestaltung von Wertschöpfungsprozessen. Zwei wesentliche Trends sind beobachtbar: die zunehmende Desintegration von Produktionsprozessen und die Neuinterpretation der Rolle des Kunden im Wertschöpfungsprozess. Im Rahmen von drei empirischen und einer konzeptionellen Analyse werden wesentliche Implikationen für die erfolgreiche Gestaltung von Wertschöpfungsprozessen abgeleitet und erwartete Erfolgswirkungen struktureller Veränderungen entlang der Wertschöpfungskette kritisch reflektiert

Stakeholders' reactions toward iodine biofortified foods : an application of protection motivation theory and technology acceptance model

This doctoral dissertation investigates stakeholders’ reactions toward iodine biofortified foods. Iodine deficiency alone affects over 2 billion people worldwide, and is particularly prevalent in developing countries. Iodine is an essential trace element found in seafood and iodized salt, as well as certain vegetables and is important for growth and development throughout the body, as well as cognitive development. Given the critical role of iodine in human nutrition, various strategies have been implemented to reduce iodine deficiency and Iodine Deficiency Disorders (IDD). However, despite considerable progress through iodine fortification, the goal is still far from being achieved. Therefore, there is a need to explore the potential of new approaches, such as iodine biofortification. Biofortification is a strategy to enhance micronutrient concentrations in staple crops, either through conventional or transgenic breeding techniques. Given its status as an agriculture-based, micronutrient strategy, a thorough insight into stakeholder reactions is necessary, examining stakeholders from both the demand-side (consumers) and the supply-side (farmers). A conceptual framework bringing together behavioural change models, technology acceptance modelling and an economic valuation technique was developed and tested for use in stakeholder analysis. Six distinct studies were conducted, targeting locations drawn from three East African countries: Kenya; Uganda; and Tanzania, which have high levels of iodine deficiency disorders (IDD) as well as retarded mental and neurological development coupled with poor school performance. These locations meet the criteria for iodine deficiency endemic areas with a large at risk population that seldom benefits from the existing intervention programs. All model constructs in the framework are decisive in determining the uptake of iodine biofortification. Consistent with evaluation of food with nutritional benefits, stakeholders on both the demand (parents and school heads) and supply-side (small-scale farmers) had favourable reactions towards iodine biofortified food, the uptake of which could drastically change the trend in iodine intake in iodine deficiency endemic areas. These findings present a niche opportunity for producers to tap into the demand market created. In principle, the findings could shape the policy terrain for addressing iodine deficiency, as well as ameliorating the nutrition intervention campaign through agricultural-based interventions, such as biofortification

Online Ratings and Reviews: Are numerical ratings more persuasive than written reviews?

In this thesis, the aim is to investigate the effect of numerical values and words on the consumer decision process. Previous research has studied the effect of online rating and review systems and how they influence consumer behavior and purchase decisions. While some studies have argued that reviews have a greater impact on users, others have argued that rating scores are more important. The main purpose of this study is to question whether participants are more affected by numerical data. In order to understand this relationship, an online experiment was conducted to analyze people’s preference on numeral ratings and written reviews and how these two elements in a website affect their behavior. The online experiment with a survey was conducted on 303 participants, mainly NHH students. We tested three types of products: books (Goodreads), restaurants (TripAdvisor) and coffee machines (Amazon). Two dummy pages were created for each product type, one of them had high numerical rating and negative written reviews, the other one had low numerical rating and positive written reviews. Instead of showing all three categories to the participants, they were shown two of them. Results illustrate that participants prefer the combination of low numerical rating and positive written reviews rather than the combination of high numerical rating and negative reviews. In addition, participants that preferred high numerical rating and negative reviews had higher level of confidence than the other group. Furthermore, we present a nuanced discussion based on the presented results and findings.nhhma

The impact of negative reviews on online search and purchase decisions

Despite evidence indicating the significant influence of online reviews on purchase decisions, even after considering a product's average rating ( Vana and Lambrecht 2021), the underlying factors behind this effect and the broader impact of reviews on consumer decision making remain uncertain. This study uses clickstream data from a major online retailer to explore how negative reviews affect consumer search and purchase decisions. Leveraging exogenous variation created by the display of online reviews sorted by recency, the authors find that negative reviews significantly reduce a product's purchase probability because they (1) contrast with the often-high average product rating, (2) decrease the probability that consumers continue browsing for information about the focal product, (3) increase the probability of visiting the page of substitute products, and (4) increase the probability of viewing reviews about substitute products. Importantly, these effects apply to utilitarian products but not hedonic products and when reviews pertain to product functionality or customer service but not to taste-related factors. The authors estimate a product's vulnerability to negative reviews along two dimensions—purchase and search probability for substitutes—and display these effects on a two-dimensional map