Our Purpose

Our purpose is to improve the value of data as a tool for promoting sustainable development and addressing the climate crisis.

Dual Citizen was founded in 2010 amidst a global economy in turmoil. Besides the financial crisis, global stakeholders were beginning to realize the system-wide risks posed by climate change, and the complexity of policy frameworks, investment, innovation, and social change required to address it. It was clear that climate change, sustainable development, and the green economy emerging around it would become central to the global economy in the coming decades.

Against this backdrop, we published the first Global Green Economy Index™ (GGEI) in 2010. At the time, it was a limited but impactful effort: it only covered 27 countries and only measured how experts “perceived” these nations as actors in the green economy. From that point until today, the GGEI, our consulting, and thought-leadership around it have grown enormously. And our client engagements have consistently been fascinating, working with a diverse range of partners in government, international organizations, the private sector and recently, ESG asset managers.

We designed this website to present more detail on how we deliver this purpose in practice. Explore how we bring unique people (see below) and perspectives to our work through our founder and strategic advisor network; how we work with clients and partners on consulting engagements; why we publish the Global Green Economy Index™ (GGEI) and the distinctive value it brings to the topic; how we approach understanding linkages between carbon emission reductions and the broader economy; and speaking engagements around the world sharing this knowledge with our partners.

We hope you enjoy it and look forward to your feedback. Sign up for our newsletter for periodic updates about the practice, including data packs and other insight from the Global Green Economy Index™ (GGEI)


The Dual Citizen LLC practice is run by GGEI Creator Jeremy Tamanini and supported by a team of strategic advisors.

Jeremy Tamanini
Strategic Advisor
Andrea Bassi
Strategic Advisor
Karuna Ramakrishnan
Strategic Advisor
Marcus Andersson
Strategic Advisor
Steve Hamilton


The Dual Citizen practice revolves around data analytics and promoting sustainable development for a diverse range of stakeholders and geographic contexts. Through consulting assignments, proprietary research and global engagement, we partner with clients to apply expertise in these areas to reorient and accelerate their companies, organizations and institutions on greener growth pathways. 

Our flagship knowledge product, the Global Green Economy Index™ (GGEI) provides a baseline for understanding national performance in the green economy, how it is judged by global practitioners, and how data and communications can help leaders improve on these results. But in many cases, the GGEI is also an entry point to more tailored consulting engagements, designed to look deeper at issues touched upon in the GGEI, but requiring further geographic localization, market sensitivity, or sectoral specificity. Some examples of customized consulting offerings that can complement a Subscription to the GGEI.

In the age of “big data,” we have ample information at our fingertips. But, often we lack the analytical expertise to synthesize them into a framework that is useful. Given our experience creating the GGEI and advising other organizations on index development, we help clients create bespoke sustainability measurement frameworks. These engagements help clients to define the key topics driving their sustainability strategy, locate the right data sets to measure them, and integrate them into an appropriate measurement framework for the desired target audience. In addition to supporting clients on the structure and methodology, we can also advise on data selection and strategies for addressing the ever-present challenge of missing data or lack of availability.

Contact us - we'd love to hear from you.