"It's possible that Hon. Gerry Brownlee is right that a Christchurch Convention Centre could get a lot of overflow traffic from Auckland. Perhaps the new Auckland centre will generate a ton of international excitement about New Zealand as a convention destination, and conference organisers finding out that Auckland is fully booked will decide to stick with New Zealand and come to Christchurch instead. I'm not sure that I'd bet a lot of money on that happening, but it isn't impossible."
"And, Minister Brownlee is also right that some parts of Convention Centre business do not cannibalise across different centres. Armageddon Expo visits each of the main centres, for example. And national organisations will often shift their annual conventions across different centres in rotation; again, a nicer Auckland centre doesn't cannibalise that kind of traffic. But whether expansive convention centres in both Auckland and Christchurch would tend to do more to build international demand for New Zealand in total or to split the "let's have our conference in New Zealand this year" market, well, it would be interesting to see the business case backing that call."As best I'm aware, we as yet have no business case for the proposed Christchurch convention centre. I'd be interested in perusing the document when it comes into existence.