Lucas is a prolific writer of reports, articles and books on the subjects of trade justice, localisation, globalisation, animal welfare, and food, in which she is critical of free trade, a single European currency, trade-led development policies, genetically modified food, and a lack of attention to environmental and social issues. Her most substantial work is Green Alternatives to Globalisation: A Manifesto (co-authored with Mike Woodin), which advocates localisation of economies based on minimal trade and greater social and environmental concern, in opposition to neo-liberal, market-led forces of globalisation.
