Essentially, a gravity model suggests that the flow (of migrants, trade, or students) between two places is positively related to the 'economic' size of the origin (more potential migrants, or more things to trade), the economic size of the destination (more opportunities for migrants, or more demand for tradeable goods), and negatively related to the distance between the two places (since movements over longer distances are more costly). The gravity modelling approach does a pretty good job of explaining trade and migrant flows, even without including any other variables - whether they be factors in the origin that 'push' migrants out, or factors in the destination that 'pull' them in.
Cullinan and Duggan include both school-level variables (push factors) and tertiary-institution-level variables (pull factors) in their models. They find that:
...school size, girls-only schools, mixed-gender schools and Catholic schools are associated with higher students flows, all else being equal. On the other hand, schools with DEIS [disadvantaged] status are found to be associated with lower student flows. The effect for schools located in more deprived areas is somewhat surprising, suggesting flows are lower from schools located in more affluent areas.Given that they have already controlled for schools that are considered disadvantaged, that last result might not be as surprising as it seems. The size of the effect is tiny. They also note that:
...HEIs [Higher Education Institutions] located in Dublin are found to have lower predicted student flows once the other factors are accounted for, an effect that may be driven by the higher costs of living in the capital city.It might also be because the top two universities (Trinity College Dublin and University College Dublin) are both located there, and will be the most selective in terms of their student intakes. Finally, one other result I found particularly interesting (though not necessarily surprising):
...the average [distance] elasticity masks considerable variation both within and across HEI types, suggesting that students are much more willing to travel further to attend some HEIs than others.Specifically, the distance elasticities were lowest for Trinity College Dublin and University College Dublin, as you might expect for the highest quality universities.
It would be really interesting to repeat a similar analysis for New Zealand, and I expect the IDI holds the necessary data (it certainly has tertiary data and secondary school data - the question is whether they are easily linked). This would be even better than the Irish study, as there are many years of data available, rather than just a single cross-section. There's definitely a potential future Honours or Masters project in that.