Who tips, and who complains in UK restaurants, and what happens when they do?

This thesis investigates customer behaviour in UK restaurants across four interconnected discretionary responses to a dining experience: the decision to complain at the time following a service failure, the decision instead to complain anonymously online afterwards, the decision to reward good service through a tip, and the decision to reward it through a positive online review. It asks why some customers complain at the time, and others stay silent, why some tip readily while others do not, why some prefer to reward or critique online after the meal, and how individual differences and situational factors shape these outcomes. Each chapter is organised around three parallel research questions: whether demographic and socio-economic characteristics (age, gender, income) relate to the behaviour (Research Question 1); whether personality measures are associated with it, and in what direction (Research Question 2); and how the circumstances of the dining experience, including staff actions and, for tipping, the presence of a service charge, relate to it (Research Question 3). To address these questions, a three-study, mixed-methods, longitudinal design integrated quantitative and qualitative evidence. Study 1, an online survey of 790 UK diners, assessed their propensity to complain at the time, to complain online afterwards, or to do nothing, alongside their tipping behaviour, personality traits, and socio-economic and demographic characteristics. Study 2 extended these findings through a year-long longitudinal study tracking 98 customers across 994 measurable dining occasions, recording meal characteristics, staff interactions, and behavioural outcomes after each visit. Of these occasions, 251 involved a service fault and formed the basis of the complaint and negative-review analyses. Study 3 comprised in-depth interviews with 35 participants: 20 diners (ten verbal complainers and ten tippers, each comprising five highest and five lowest in propensity, all different individuals) and 15 restaurant staff drawn equally from operational, supervisory, and managerial levels (five of each), to provide contextual and managerial explanations of the quantitative patterns. The diner outliers were identified by their verbal-complaint and tipping propensity rather than their online-reviewing behaviour. Across the three studies, personality emerged as the most consistent influence (Research Question 2). For complaining, customers higher in entitlement, redress orientation and extraversion were more likely to complain, whereas those higher in empathy complained less and, when they did become dissatisfied, were less likely to voice it. The same empathy that suppressed face-to-face complaints also predicted reward behaviour, as empathic and older diners were markedly more likely to tip, along with the trait of altruism. Addressing Research Question 3, situational and staff factors were equally important. Being made to feel special on arrival independently raised the likelihood of tipping and, alongside service satisfaction and friendliness, motivated positive reviews, while reducing both dissatisfaction and the likelihood of complaining. Among customers whose fault was resolved, being made to feel special immediately was the strongest protective factor against a negative online review, and successful staff recovery neutralised the personality traits (entitlement, neuroticism, conscientiousness) that otherwise drive negative reviews. The presence of a service charge sharply reduced voluntary tipping, with propensity falling from 64.4% without a charge to 23.9% with one (in addition to the charge). When the service charge was applied, total gratuity revenue per occasion more than doubled on average, a finding with direct implications for the UK Employment (Allocation of Tips) Act 2023. Addressing Research Question 1, demographic and socio-economic effects were more selective and generally weaker than personality and situational predictors. Age and income were both associated with tipping, and age was a weak but significant predictor of complaint propensity, while gender and income were not. For online complaining, income and gender were only nominally associated and did not survive correction for multiple comparisons. The income effect on tipping did not persist once behaviour was measured visit-by-visit. Of the 251 fault occasions in the longitudinal study, the majority were absorbed silently or handled informally rather than escalated, and among customers who said nothing to staff, neither personality nor situational factors reliably predicted whether they later reviewed, suggesting a values-based disposition not to review. Positive reviewing followed a different logic and was driven less by situational factors and more by the importance of the occasion and whether the customer was a regular at the restaurant, marking it as a reward expressing loyalty rather than immediate gratitude. These patterns indicate that complaining and rewarding each have an at-the-time, in-person channel and a delayed, anonymous one, and that the determinants of these anonymous channels (Tripadviser for example) differ greatly. This underscores the importance of staff training and managerial awareness in resolving faults in a timely manner, before dissatisfaction turns into a negative review. The thesis advances theoretical understanding of consumer behaviour in hospitality by integrating complaining, tipping, and online reviewing into a single framework that extends SERVQUAL and Johnston's zone-of-tolerance theory to incorporate individual differences, the full positive-to-negative behavioural spectrum, and the role of early staff interaction. Ultimately, the study presents a dual outcome theory that includes staff interactions, individuals' personalities and moods, and the quality vs expectation impact, captured in a new organising model. Martin's Theory of Restaurant Tipping Points represents the behavioural outcomes as counterweights on a single balance, tipping either towards positive or negative outcomes depending on factors from the thesis. It argues that established consumer-decision models require adaptation to capture the emotional and interpersonal dynamics of restaurant service. That the same satisfaction or dissatisfaction may be expressed either at the time or after the meal, via an anonymous online channel, depending on the customer's disposition and the situation. In practice, the findings equip managers with evidence-based guidance to resolve faults before they lead to negative reviews, to encourage tipping through early staff interactions, and to navigate the introduction of service charges. This final element of the study speaks directly to the policy questions raised by the Employment (Allocation of Tips) Act 2023.