This thesis discusses whether participation in two voluntary sustainability standards (VSS) has improved the capacity of coffee producers to upgrade, and the extent to which it has brought economic benefits and reduced their exposure to risk and vulnerability. These debates are addressed using the Global Value Chain (GVC) perspective, including recent contributions that integrate poverty considerations, to assess the implications for coffee growers of participating in the specialty coffee value chain. In this analysis, particular emphasis is given to differences according to farm size. The study focuses on the Nespresso AAA Sustainable QualityTM programme and Fairtrade certification in Colombia, comparing the two treatment groups with a control sample of similar conventional producers. In addition to this, a comparison between two groups of AAA producers was carried out. The data comes from three rounds of surveys and two periods of field work. To assess differences over time and construct a robust counterfactual this thesis combines Propensity Score Matching (PSM) with the difference-in-difference (DID) analytic approach. VSS initiatives have been promoted as a way of improving the livelihoods of small producers, with extensive implementation in coffee production. The analysis shows that interventions to facilitate upgrading and support the involvement of producers in VSS do not produce consistent improvements over time for most of the indicators analysed. Therefore, the potential of VSS to generate significant improvements in livelihoods for certified producers, could take both a longer time and require greater institutional efforts to build capacities. This finding needs to be considered in light of strong institutional support for all coffee producers in Colombia, which could offset the impact of VSS support. In terms of livelihood-related variables, the analysis shows that participating producers became more dependent on coffee revenues (as there was no significant expansion of cash production), reduced their share of haired labour during the period of study and paid these workers less than the minimum wage. These trends are similar to those of the conventional producers, since the analysis did not find significant differences over time. The outcomes of the analysis by farm size draws a bleak picture for smallholders below one hectare. The main conclusion that can be drawn from the evidence is that the farm size constrained both the potential upgrading opportunities from VSS and their chances of gaining sustainable incomes. The political economy effects of these disappointing results, both for certified producers and producers thinking about certification, must be analysed carefully, as growers' expectations of improving their economic and social viability through the adoption VSS are lower than expected. As such, VSS initiatives cannot be the only strategy for helping very small coffee producers to overcome the structural restrictions and limitations they have faced for decades.

This thesis challenges accounts of individual choice and responsibility where food consumption is concerned, beginning with a critique of government policies to address the health effects of over-consumption of food. Whilst research from psychology and economics has acknowledged the role of habit and automaticity in some behaviours, including eating, the resulting theory of behavioural economics and its operationalisation as ‘nudge' theory does not directly address class differences. I argue that sociological analysis can do so, and discuss the trajectory of social class in social theory in recent decades, bringing together the insights of several theorists to challenge both Giddens's concept of reflexivity and postmodern notions of consumerism as an equalising force. I demonstrate that social theory can provide a solid underpinning to behavioural economics, and at the same time show the weakness of its policy applications to healthy eating. Given the relative inattention to the structures that shape dietary ‘choices', in comparison to the study of behaviour, this thesis examines the nature of the food supply and traces how the food industry develops, markets and sites food, and the ways in which it engages, often interactively, with a highly segmented society. The production and targeted supply of processed foods of varying quality contributes to problematic food consumption, particularly among those of lower social status. This phenomenon is further evidenced by an epidemiological review outlining the food-health-class link. Subsequently, I conduct the first sociological analysis of food industry texts (representing food science, product development and marketing), revealing how actors within these disciplines articulate their role, function and concerns regarding current practice. A critique of marketing emerges from both practitioners and marketing academics, and I apply this and an expanded sociological critique to the role of the food supply in diet-related ill health, in which a social gradient is strongly apparent.

Climate variability and climate change have become important research topics also in economics. The objective of this thesis is not to forecast the future but to learn from the past by studying how two important climate change-related topics have affected Indonesian households. Delayed monsoon onset, El Niño, will become more frequent with climate change whereas palm oil production is a contributor to climate change. The first essay examines how variability in monsoon onset affects rural households' welfare in terms of household expenditure and farm profits. Using the Indonesia Family Life Survey (IFLS) data I find that households in the middle tercile of the expenditure distribution face the biggest albeit temporary losses from delayed monsoon onset. Half of the expenditure decline is due to increase in household size. Conditional on onset, rainfall intensity has only minor effects. The second essay uses the IFLS data to study how schooling and child labour are affected by delayed monsoon onset. The probability of continuing from primary to secondary school is reduced when a delayed onset coincides with the transition year. In other respects, monsoon onset does not affect education of rural children. However, riskier distribution of rain postpones school entry for young children. Moreover, delayed onset increases child labour. Using district-level data on palm oil production and area planted and national household survey (SUSENAS) the third essay studies the impact of oil palm expansion on household expenditure and health. Instrumental variable estimates exploit the historical production and district forest area as an exogenous source of variation. I find that smallholder production has a weak negative impact on household expenditure but this effect is not present among rural households. More, total production increases incidence of asthma in Kalimantan. The findings suggest that palm oil is not a panacea to increase rural welfare.

While it is clear that urban food systems need to be made resilient so that broader sustainability goals can be maintained over time, it has been a matter of debate as to how resilience should be conceptualised when applied to social-ecological systems. Through a case study of peri-urban Wuhan, this research develops and applies a resilience based conceptual framework for periurban food systems analysis in order to explore the potential for an enhanced understanding of resilience that can contribute to promoting sustainability in urban food systems. The evidence of this thesis suggests that the current approach to governance of Wuhan's periurban vegetable system is building an increasingly exclusionary pattern of resilience. It is a form of resilience building which is likely to undermine broader normative sustainability goals around social justice and environmental integrity and have mixed future implications for food system resilience as a whole, particularly in relation to livelihood outcomes for peri-urban farmers and food safety outcomes for urban consumers in general. The key lessons from this research are that the concept of resilience can be used to support either a narrowing down or an opening up of normative framings of system outcomes and can contribute to obscuring or revealing the multiple processes of change unfolding across the levels of system context, structures and actors. These dualities in the way that resilience thinking can contribute to normative and analytical framings need to be explicitly acknowledged if serious unintended consequences of resilience building interventions are to be avoided. Six important principles for conceptualising resilience in urban food systems are suggested: to 1) disaggregate system outcomes, 2) differentiate function and structure, 3) analyse positive and negative resilience, 4) identify external and structural shocks and stresses, 5) analyse resilience in relation to multiple and multi-scale processes of change and 6) recognise the impacts of those processes on marginalised system actors. Finally, a heuristic framework is presented for guiding the design of resilience analyses of human dominated social-ecological systems.