Summary
Using a modified systematic review approach, the report authors reviewed 51 studies that examined the impact of agricultural VSS participation on five livelihood-related outcomes: yield, input costs, crop prices, crop income, and net household income. In all, 208 individual results for these five outcomes were analyzed. The findings show that the volume of research on this subject has increased over time, with a peak in 2016. Africa was the most frequently-studied region, coffee was the most frequently-studied crop, and Fairtrade was the most frequently-studied VSS, results that are consistent with previous reviews conducted by Oya et al. and DeFries et al. Over half of the results that examined the price farmers received and the income they earned from their certified crop found that VSS-certified farms performed significantly better than non-certified farms. Although critical to our understanding of farmers' financial wellbeing, net household income was the least-studied outcome, and had the highest proportion of results showing no difference between VSS-certified and non-certified, at just over two-thirds. Net household income was significantly higher on VSS-certified farms in one-quarter of results. Results suggest that additional research is needed to clarify the influence of farmer cooperatives, disentangle the relationship between yield, price, and net household income, and better understand the tradeoff between crop specialization and off-farm employment.