Emma McGuirk (who founded the Dunedin Timebank) did her PhD thesis looking at 7 North Island Timebanks in 2017.  The full thesis is not available online but her abstract is available here:

McGuirk, E. (2017). Timebanking in New Zealand: Academic and Activist Discussions of its Challenges and Pleasures (Thesis, Doctor of Philosophy). University of Otago. Retrieved from http://hdl.handle.net/10523/7445

McGuirk, E. (2017). ‘Timebanking in New Zealand as a prefigurative strategy within a wider degrowth movement’ Journal of Political Ecology 24:595-609.

McGuirk, E. (2012). ‘Studying Time Banking: Exploring Participatory Action Research in Aotearoa New Zealand’ Sites: A Journal of Social Anthropology and Cultural Studies 9(2):142-171.

And here is Emma in person with Matt Slater and Arthur Brock talking about the idea of a Co-op Coin on YouTube.

A growing collection of publications on TimeBanking in New Zealand, featuring the reasearch of Lucie K Ozanne. Lucie is the Associate Professor of Marketing at Canterbury University. Lucie has been involved with TimeBanking from its early beginnings in New Zealand. 

Lucie K Ozanne & Julie L Ozanne (2013)  Developing Local Partners in Emergency Planning and Management - Lyttelton TimeBank as a Builder and Mobiliser of Resources during the Canterbury Earthquakes

Lucie K Ozanne (2012) - Learning to Exchange Time  Benefits and Obstacles to TimeBanking

Lucie K. Ozanne & Julie L. Ozanne, (2016) How Alternative Consumer Markets Can Build Community Resiliency

Tephra (2012): Community Resilience  Case Studies from the Canterbury Earthquakes

Lisa Geary (2010) Fesability Study on a Canterbury University TimeBank