Figure 1 shows hypothetical flows between Scotland and the rest of the UK. Flows are indicated by arrows, and those arrows that are shaded grey are captured in the relevant census. The arrow marked ‘a’ represents those people moving from the rest of UK to Scotland in 2021-22 and (if they completed the form) captured in both censuses. The arrow marked ‘b’ represents those moving in the opposite direction and captured in neither. Does Scotland’s population show a false gain, through singapore rcs data arrow ‘a’? No, because the ‘b’ flow has still taken place – people have left Scotland – and whilst they are not captured as individuals, their removal from the aggregate observation for Scotland has still occurred. Similarly, those in arrow ‘c’, who moved to Scotland in the year 2020-21 are not recorded (as migrants), but the change to aggregate stocks is still apparent.
Of course, we would like all individuals to be reflected correctly in the data. In ‘normal’ times, we might assume that migrants have broadly similar characteristics: those who moved to Scotland in 2021-22 (arrow ‘a’) were similar to those who moved to Scotland in 2020-21 (arrow ‘c’), and so on. If this were the case, then we might think that the situation is not too bad – the similar sizes of flows means that stocks are not strongly affected, and the similarity of characteristics would that our aggregate observations would be consistent.
However, it is clear that we cannot assume similarity in characteristics of those moving at different stages in the pandemic. Some people remained in work (and those with jobs that could be conducted remotely may have had a broader choice in relocation destinations), whilst others were out of work or furloughed. Variations in the regulation of housing markets in both Scotland and in the rest of the UK will have affected the feasibility of moves, both for owner occupiers and for those renting.