Is Scottish independence inevitable? The relationship between birth cohort and secessionism in Scotland.

By Mark McGeoghegan

For the reason that 2014 independence referendum, a debate over the connection between age and help for Scotland seceding from the UK has flared up frequently. Polls constantly present that the youngest voters are more likely than older voters to help Scottish secession. The most up-to-date Norstat ballot for the Sunday Instances discovered that amongst seemingly voters, 67% of these aged between 16 and 34 would vote Sure to independence, in comparison with lower than 40% amongst these aged 55 and over. It isn’t uncommon for polls to seek out even larger gaps between the youngest and oldest voters, and these figures are routinely deployed in arguments over whether or not Scottish secession is just a matter of time.

These arguments have a tendency to interrupt down alongside partisan traces. Supporters of secession usually make what is likely to be referred to as the ‘actuarial’ argument: as older, much less secessionist voters cross away, and as youthful, extra secessionist voters come of age and exchange them within the voters, the extent of total help for secession will rise till a persistent majority are in favour of Scottish secession. Their opponents usually reply with an argument rooted in prospect idea: as youthful voters age, they’ll grow to be extra threat averse – as a result of having a mortgage, pension, financial savings, kids, and so forth – and thus will grow to be much less prone to help radical insurance policies usually and secession from the UK particularly. That is, primarily, a variation on the argument that voters grow to be extra conservative as they age.

It is a slight oversimplification – it’s, in fact, doable for each mechanisms to be in impact – however it captures the final state of the controversy. Till now, these arguments have been made with little empirical proof in favour of both, however they current us with clear hypotheses that may be examined.

On the coronary heart of this debate is a single key query: is the connection between age and help for Scottish secession a cohort impact, a lifecycle impact, or a cohort impact mediated by a lifecycle impact? Cohort results confer with variations between beginning cohorts that persist over time, whereas lifecycle results confer with modifications that happen amongst a beginning cohort as they age. A 3rd kind of impact, interval results, refers to occasions that shift each beginning cohort on the similar time.

The modelling I’ll now set out means that there was a constant cohort impact since 1999 – that’s, voters in youthful beginning cohorts usually tend to help secession than voters in older beginning cohorts, and it is a persistent discovering over time. It additionally fails to seek out proof of a lifecycle impact – beginning cohorts don’t grow to be much less prone to help secession as they age. We additionally see interval results across the 2014 and 2016 referendums, when occasions reshaped Scottish politics.

These findings have to be fastidiously interpreted. Firstly, with solely 24 years of knowledge and only some waves of knowledge for the youngest voters, it’s unimaginable to say that no lifecycle impact will ever kick in; there may be simply no proof of 1 but. Secondly, this doesn’t imply that independence is a matter of when, not if – every week is a very long time in politics, and the generational timescales we’re discussing right here can comprise many unpredictable modifications that reshape public opinion. Nonetheless, it does recommend that the actuarial argument outlined above is best supported by empirical proof.

Modelling Help for Scottish Secession by Start Cohort

To start to reply this query, I used information from the Scottish Social Attitudes Survey[1] collected between 1999 when the research first launched, and 2023, when its most up-to-date wave was performed, offering 20 waves of pattern information over the course of 24 years (no survey was performed in 2008, 2018, or 2020, and I exclude the 2021 wave for the explanations outlined within the Scottish Authorities’s publication of the 2023 wave[2]).

The Scottish Social Attitudes Survey asks respondents ‘which of those statements comes closest to your view?

Scotland ought to grow to be unbiased, separate from the UK and the European Union.Scotland ought to grow to be unbiased, separate from the UK however a part of the European Union.Scotland ought to stay a part of the UK, with its personal elected parliament which has some taxation powers.Scotland ought to stay a part of the UK, with its personal elected parliament which has no taxation powers.Scotland ought to stay a part of the UK with out an elected parliament.’

The primary two reply choices sign help for Scottish secession from the UK, and the latter three help for Scotland remaining a part of the Union. I used this query, slightly than the 2014 Scottish independence referendum query, for 2 causes. Firstly, the Scottish Social Attitudes Survey has not constantly requested the referendum query over time, and publicly obtainable datasets that do and match the pattern high quality of the SSAS, such because the Scottish Election Research, are much less frequent, with far fewer years of pattern information. Secondly, the 2014 referendum query won’t essentially be the query used the subsequent time Scotland holds an independence referendum (if it ever does). It’s extra applicable to make use of a measure that enables respondents to choose particular governing preparations, a choice that will underpin voting intention in a future referendum.

I mixed the primary two reply choices and the latter three reply choices to create a binary measure of help for Scottish secession. That is the dependent variable I’ll mannequin over time to evaluate whether or not there’s a cohort impact on help for Scottish secession and whether or not the chance {that a} member of a given cohort’s help or opposition to secession modifications as they age.

I categorised the Scottish Social Attitudes Survey respondents into six beginning cohorts:

Born earlier than 1958

Born between 1959 and 1968

Born between 1969 and 1978

Born between 1979 and 1988

Born between 1989 and 1998

Born between 1999 and 2007

I then carried out two kinds of modelling. Utilizing the complete set of knowledge from 1999 to 2023, I constructed a mixed-effects logistic regression mannequin with help for secession because the dependent variable and beginning cohort as our key unbiased variable. I additionally managed for intercourse and residential possession, taking into account that males had been extra prone to help secession in 2014 and residential possession is a generally cited think about encouraging larger threat aversion (I management for relative prosperity and whether or not a respondent has kids in year-specific modelling beneath, however such information isn’t obtainable for all years).

The findings of this mannequin are introduced within the desk beneath and might be interpreted by inspecting the chances ratios. For instance, the chances {that a} member of the youngest beginning cohort helps Scottish secession are 3.12 instances larger than the chances for a member of the oldest cohort. Likewise, the chances that males help Scottish secession are 1.28 instances larger than the chances for girls. In distinction, the chances that owners help secession are 42% decrease than these for non-homeowners. All of those relationships are statistically vital on the most stringent typical stage (p < 0.001).

To additional examine these relationships over time, I additionally performed year-specific logistic regressions. It could devour far an excessive amount of area to current every mannequin individually[3], however these fashions discover that the cohort impact on Scottish secessionist help was persistent for a lot of the interval between 1999 and 2023, and it was in 2014 that the up to date hole in constitutional preferences between youthful and older beginning cohorts turned cemented.

One of the best ways to reveal that is by wanting on the modelled possibilities {that a} member of a given beginning cohort helps Scottish secession over time. That’s what the chart beneath does. There’s a persistent and clear cohort impact however no decline in secessionist help inside beginning cohorts. Certainly, occasions surrounding the 2014 and 2016 referendums seem to have grown help throughout cohorts however to not have tightened or modified the gaps between cohorts.

Conclusion

We began with a transparent query: is the connection between age and help for Scottish secession a cohort impact, a lifecycle impact, or a cohort impact mediated by a lifecycle impact? This evaluation ought to lead us to reject the speculation that there’s a lifecycle impact at work, at the least till the passage of time, the gathering of extra information, and a reappraisal of the information convinces us in any other case.

This isn’t the identical as saying that there isn’t any lifecycle impact at work or that no such impact may emerge sooner or later. However there isn’t any proof for such an impact proper now.

In flip, it could be cheap for advocates of the actuarial argument outlined above to take this evaluation as supportive of their argument. Nonetheless, it shouldn’t be taken as proof that independence is inevitable. Public opinion is mutable, not set in stone. As we will see above, interval results can shift opinion throughout the inhabitants – they’re additionally not essentially predictable. If we had been wanting on the chart above in 2010, with none subsequent information, we’d have been unlikely to foretell the 2014 independence referendum or the 2016 EU membership referendum, by no means thoughts black swan occasions just like the COVID-19 pandemic.

We also needs to keep in mind that campaigns can change opinion, too. It’s completely doable that youthful beginning cohorts could be extra vulnerable to threat aversion if the prospect of independence was actual, with an upcoming vote, and the unionist facet targeted on such arguments.

Briefly, this evaluation gives some early proof to supply a larger empirical underpinning of debates across the relationship of age to help for Scottish secessionism, however it’s removed from the ultimate phrase.