What do we know about the effects of military conscription?

Mounting national security threats have led a number of European countries to consider reinstating mandatory military service. Proponents argue that it would bolster national defence and boost citizenship among young people. But evidence on either effect is scarce or points to the opposite outcome.

Russia's invasion of Ukraine has spurred many European nations to strengthen their militaries. This includes boosting defence budgets and growing the size of their standing armies.

Budget increases are underway to address the historically low levels of defence spending by many European members of NATO. Many have dropped far below NATO's target of 2% of GDP. The UK has met the target, spending 2.2% of GDP in 2022, but France, Germany and Italy are examples of countries that have fallen shy, spending 1.9%, 1.4% and 1.7% respectively (World Bank).

Addressing troop shortages is arguably a more intricate challenge, where money can only address the issue to a certain extent. Indeed, European countries have long struggled with declining recruitment rates.

This challenge has led many politicians, from across the ideological spectrum, to advocate the return of conscription as a cost-effective tool to protect national borders. Latvia, Sweden and Ukraine have all reintroduced conscription in recent years.

Beyond pure defence considerations, some see an additional benefit in conscription – a romantic view of it as a ‘school of the nation’, fostering national values in young citizens.

But compelling evidence that supports conscription achieving either of these core objectives – protecting national borders or instilling feelings of citizenship – remains elusive.

Does conscription address security needs?

Proponents of conscription argue that nations facing significant external threats need a large military to bolster their defences and deter aggression. While this holds in principle, a critical question that remains open is whether the relatively short duration of compulsory military service (Poutvaara and Wagener, 2007) is sufficient to equip conscripts with the skills demanded by modern high-tech warfare (Toronto and Cohn, 2020).

Proposals to reintroduce conscription often refer to short terms of service, lasting months rather than years. For example, the Conservative party in the UK has proposed reintroducing 12 months of mandatory national service if it wins the general election on 4 July 2024.

This short timeframe raises concerns about whether conscripts may become liabilities rather than assets. ‘Building’ a soldier takes time – how long varies depending on the specific role.

Training in complex fields – such as communications and cyberwarfare – lasts years. But even in basic infantry roles, transforming raw recruits into competent soldiers is far from an immediate process.

A few months of service might provide draftees with basic skills and knowledge. But these are unlikely to be adequate for most professional army units.

To date, there is a dearth of rigorous studies on what the minimal length of compulsory military service should be, although stints shorter than two years are often deemed insufficient to create an effective fighting force (Kier, 1997).

One study shows how the reduction in the duration of conscription worldwide is strongly associated with changes in the demographic structure and education levels of (young, male) citizens (Tarabar and Hall, 2016).

Specifically, countries with a higher proportion of older citizens tend to have longer conscription stints, although this relationship reverses once the older population surpasses a certain threshold.

In addition, the length of military service tends to decrease in regions where a larger share of young male citizens has completed secondary education. In OECD countries, there is a negative correlation between real GDP per capita and conscription duration, while in non-OECD countries, this relationship is positive.

This divergence is due to varying economic incentives and constraints in these groups of countries. Taken together, these findings suggest that political and economic concerns, rather than military priorities, drive policy-makers’ decisions about the length of military service.

The potential absence of motivation and incentives among conscripts further compounds the lack of training and experience. Unlike professional soldiers, draftees may exhibit lower productivity due to motivational factors.

As one study aptly points out, forcing everyone into military service holds the same logic as mandating citizens to become teachers, nurses or heart surgeons – not everyone thrives in such roles (Poutvaara and Wagener, 2007). This can erode morale and decrease performance, especially within modern warfare's demanding and high-pressure environment.

At the same time, loopholes in medical exemptions and discretionary power at the local level create opportunities for wealthy individuals to exploit the system and evade compulsory service (Ingesson, 2024).

Yet it may be that conscription – by providing civilians with a first, intensive exposure to the military – could encourage retention in the army, at least in the short term. To our knowledge, no extant empirical research has investigated this link, at least in the context of European armies.

Is conscription cost-effective?

While conscription may seem a cost-effective way to staff the military, it is not without economic drawbacks. Governments often focus solely on budgetary costs when comparing all-volunteer forces to conscript ones.

Still, the net impact of reintroducing conscription on state coffers is far from obvious, due to its ambivalent effect on personnel costs: while the number of soldiers increases, their pay gets lower (Bove and Cavatorta, 2011).

But the bigger picture lies beyond the immediate budgetary concerns. Conscription forces young people to serve irrespective of their opportunity cost – that is, the value of draftees’ lost production elsewhere – and the disutility from having to work in an occupation that conscripts would not otherwise have chosen (Warner and Asch, 2001).

Recent studies using natural experiments shed light on the long-term economic effects of peacetime military service. While some show no significant impact on earnings in the UK (Grenet et al, 2011) and Germany (Bauer et al, 2012), others paint a different picture. (Note that national service ended in 1960 in the UK and in 2011 in Germany.)

Studies in the Netherlands calculate earning losses from compulsory service of 3-5% (Imbens and van der Klaauw, 1995; Hubers and Webbink, 2015). And a recent Danish study using a randomised draft lottery documents a substantial negative effect on earnings, with high-ability men facing an estimated $23,000 lifetime penalty (Bingley et al, 2020).

Educational incentives could explain these contrasting findings. Reintroducing military service can exert an ambivalent effect on enrolment rates in post-secondary education. Further, evidence on the link between the duration of military service in peacetime years and subsequent enrolment in tertiary education remains inconclusive (for a summary, see Savcic et al, 2023).

It could boost enrolment rates, as some may enrol in university to delay or avoid military service (Card and Lemieux, 2001; Maurin and Xenogiani, 2007; Bauer et al, 2014). But conscription could also harm graduation by interrupting students’ education (Cipollone and Rosolia, 2007).

In the aggregate, these economic costs could result in lower long-run national income and economic growth (Keller et al, 2022). Hence, despite its perceived cost-effectiveness, conscription can be a financially burdensome method of military recruitment.

Does conscription foster civil values?

Several European leaders romanticise conscription as a ‘school of the nation’, believing that it fosters national unity and civil values through shared experiences among diverse conscripts. Indeed, this mirrors the Conservative party’s messaging during the UK’s 2024 general election campaign.

Isolating draftees from civilian life and exposing them to national symbols and core military values should strengthen patriotism and civic obligations towards the state (Krebs, 2004). Conscription can indeed contribute to forging a shared national identity and fostering patriotic sentiment (Cáceres-Delpiano et al, 2021; Ertola Navajas et al, 2022).

But does this translate into civic support for democratic institutions?

Here is the crux of the issue: the cultural environment to which draftees are exposed tends to skew civic identity along military lines. It fosters strong ties to the armed forces, possibly at the expense of loyalty to democratic institutions.

This could weaken the citizen-state relationship, rather than strengthening it. Research suggests that, if anything, conscription decreases trust in democratic institutions (Bove et al, 2022).

By exposing young people to a hierarchical structure, a shared set of values and rules, and a cohesive community within the military, conscription policies appear to prioritise the military over democratic institutions that may already be perceived with suspicion.

Conclusion

Short conscript service periods may leave soldiers ill-equipped for modern warfare. Additionally, draftees often lack motivation, which is likely to have an impact on their overall effectiveness.

While conscription may appear on the surface to be cost-effective, mere budgetary accounting disregards the potentially high opportunity cost that young people face when forced to serve, leading to long-term earnings losses and educational disruptions. These factors combine to reduce national income and economic growth.

Lastly, far from fostering cohesion among citizens, conscription appears to weaken the relationship between the citizen and the state.

Overall, the idea of reviving conscription in Europe seems more romantic than practical. It may not address security needs effectively; it comes with hidden economic costs; and it offers doubtful benefits for national unity.