Understanding Australian and New Zealand Student Visa Approval Rates Through Origin Composition and Weighting

According to our previous study, Australia generally had higher recorded student-visa decision approval rates than New Zealand across matched applicant origins. This study tests whether that difference can be accounted for by how decisions are distributed across origins and years. Its main question is whether Australia's higher recorded rate is explained by origins with higher observed Australian rates accounting for larger shares of its decisions. The results do not support that explanation. When Australia and New Zealand were given the same distribution of decisions across origins, Australia had the higher average recorded approval rate. We used aggregate public records for 173 matched origins from 2022–2025. Using the destination-specific origin shares observed in the data, the Australian-minus-New Zealand difference was 5.3 percentage points (95% confidence interval −1.4 to 11.3; p = 0.097). In a computational comparison that applied the same average origin distribution to both destinations, the standardised rates were 88.5% for Australia and 77.6% for New Zealand. The difference therefore increased to 10.9 points (4.2–18.7; p < 0.001). The composition component was −5.6 points (−14.5 to −1.2; p = 0.005), confirming that equalising the origin distribution widened rather than removed the estimated difference. The Australian-minus-New Zealand rate component was positive in every year, but its size and the observed gap varied. The distribution of decisions therefore changed the apparent comparison, but it did not account for Australia's higher average recorded rate. These aggregate results do not explain why origin-specific rates differ or identify causal or individual effects.