Sustainability or overconsumption?

: examining the effect of gen Z consumer motivations and social media content on second-hand fashion behavior

Abstract

This thesis explores how Gen Z consumer motivations and social media content influence sustainable and excessive purchasing behavior in second-hand fashion. Although second-hand fashion is often portrayed as a sustainable alternative to fast fashion, its presentation on digital platforms increasingly reflects fast-paced, trend-driven dynamics. To investigate this paradox, a sequential exploratory mixed-methods design was applied. The qualitative phase involved focus groups and expert interviews, which confirmed and supported five key motivations previously identified in the literature, namely affordability, uniqueness, environmental concern, trendiness, and social or moral approval. These insights informed an online survey that tested their impact on overconsumption and sustainable behavior, alongside the moderating role of social media content. The results revealed that uniqueness significantly predicts overconsumption, while environmental concern fosters more sustainable purchasing. Other motivations did not show significant effects. Although no moderation effects were confirmed for social media content, further analysis indicated meaningful direct influences. Content emphasizing trends and influencer visibility tended to increase overconsumption, whereas portrayals focused on sustainability and engagement with eco-conscious content promoted ethical purchasing. These findings highlight a persistent intention-behavior gap in sustainable fashion consumption, where expressed values do not always translate into action. They also challenge traditional models such as the TRA and the TPB by emphasizing the influence of symbolic and emotional drivers in digital settings. This study contributes to marketing theory by bridging consumer psychology with platform dynamics. It also provides practical implications for resale platforms, influencers, and policymakers aiming to encourage more authentic sustainable behavior among Gen Z consumers.

Date of Award	9 Jul 2025
Original language	English
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Mónica Amâncio da Silva Borges (Supervisor)