Still sitting here in south-east England waiting for our house to sell and feeling ill, so I've resorted to some more data gathering and crunching about Edinburgh schools, focusing on which catchment secondary schools retain the most pupils from their primary feeder schools. One interesting fact: even adjusting for the fact that primary schools contain seven year groups and secondary schools only six, the primary school population is 19% bigger than the secondary. Some of this is due to rising birth rate (19% from 2003-2009, a little recent to directly account for this increase, but the earliest I've found), some will be due to pupils leaving secondary before Highers, and some will be due to going into private schools or moving out of the city.
There is much information I can't find in sufficient detail to draw conclusions (e.g. post-16 leaving rate, take-up of Advanced Highers), so the absolute numbers here aren't so important, but the difference between schools is enlightening. For comparison, I've also included the latest HMIE quality rating (simplified), school roll, and a single-figure, value-added Highers result, which takes account of all A-C Highers results and adjusts for % of free school meals, normalised to 100.
123% Gracemount High, Very good- (2013), 632 pupils, Value added highers: 26
113% Balerno High, Good (2011), 784 pupils, VAH: 43
113% Craigmount High, Good (2009), 1274 pupils, VAH: 48
102% Currie High, Very good- (2007), 812 pupils, VAH: 51
99% Leith Academy, Satisfactory- (2008), 901 pupils, VAH: 35
95% Trinity Academy, Good- (2014), 883 pupils, VAH: 33
89% Boroughmuir High, Good+ (2008), 1139 pupils, VAH: 64
89% Portobello High, Good (2007), 1336 pupils, VAH: 39
89% The Royal High, Very good- (2007), 1250 pupils, VAH: 49
84% Queensferry Community High, Good- (2009), 789 pupils, VAH: 48
82% Firrhill High, Good (2006), 1111 pupils, VAH: 53
82% James Gillespie’s High, Very good- (2010), 1129 pupils, VAH: 64
77% Broughton High School, Satisfactory+ (2011), 908 pupils, VAH: 40
77% Drummond Community High, Good (2009), 502 pupils, VAH: 34
71% Liberton High, Satisfactory+ (2014), 650 pupils, VAH: 29
64% Wester Hailes Education Centre, Satisfactory (2010), 345 pupils, VAH: 33
58% Craigroyston High School, Good (2015), 400 pupils, VAH: 15
54% Forrester High, Good (2009), 628 pupils, VAH: 25
50% Tynecastle High, Satisfactory+ (2008), 560 pupils, VAH: 26
42% Castlebrae High, Weak+ (2011), 251 pupils, VAH: 11
Gracemount probably takes a significant share of erstwhile Liberton pupils, but then Liberton probably takes some of Castlebrae's prospective pupils (two Liberton feeder schools also feed one of the other secondaries).
Schools above 100% attract more students from out of catchment than they lose from their nominated feeder primaries. Traditionally near-top-of-league-table secondaries such as Firrhill and James Gillespie's stand out as lose a significant portion of their feeder populations despite good performance in exams. Some of this will be to private schools, some may be out-of-catchment students who managed to get a place in the primary but not the secondary.
Well I found it interesting anyway.