Leigh also attracts a large number of SCUBA divers from both around New Zealand and abroad. New Zealand has an estimated 150 000 divers and Dive New Zealand often recommends Leigh in response to dive site inquires from abroad (pers. comm. Graham Older, Dive NZ). With Leigh being such a sheltered and enjoyable dive within a few hours of Auckland, a large portion of New Zealand divers would have either trained for their dive certification at Leigh or visited at some stage. Most of these dive training schools, organised trips, gear rental and sales would be based in Auckland. This contrasts again with Fiordland where hiking has less equipment, few courses, and the guided trips and gear rental is probably purchased mostly within the region. The significant spending generated outside the study area at Leigh would lead to an understatement of gross economic impacts when compared to the Fiordland study.
Implications of Study Area Size when making Comparisons between Studies Region size must be considered when comparing the results to other studies. Where a study region’s economy is small and within close proximity to a large economic centre outside the study area, as is the case at Leigh, money will cycle less within the region, making the flow-on economic impact within the region comparatively small. Where a region is large and includes centres of substantial size, more goods are supplied from within the region so money can cycle more, creating larger economic impact. For example a day visitor to Leigh might buy a $4 sandwich in Leigh for lunch which in fact was made in Auckland, and a $20 pizza in Auckland for dinner. The $2 mark-up on the sandwich is the only economic impact on Rodney. In contrast a day visitor to Milford Sound who spends the same $24 would find their sandwich was made in the region, their pizza was bought within the region, its dough was made at the same local bakery that made the sandwich, toppings were all bought locally and some were grown locally; hence the economic impact is much greater than the $24 spent, compared to just $2 in Rodney.
Increases in Study Area lead to More Substitutions and hence Lower Net Impacts If the objective of the study is to estimate a large economic impact why would researchers not simply increase their region of study? Because another key component of the analysis is to consider what people would do instead if the resource did not exist. If visitor spending would remain similar and be spent elsewhere within the region, then the economic impact does not count as being a net increase due to the resource being studied. So in Fiordland a large region could be studied as many visitors to Fiordland would not even come to the region if Fiordland did not exist. If the marine reserve did not exist at Leigh visitors might spend more time in Auckland, so to include Auckland in the region would render all this alternate spending as having no