Breaking the Waves? Education, Youth Bulges, and Armed Conflict account for. Some countries experienced up to four peace spells in the period 1970-2000. Nevertheless, the number of multiple peace spells is small relative to the total number. In the absence of an established method to correct for this dependence, this problem is therefore treated as a nuisance and ignored in the analysis. Geographic interactions between neighboring countries (which are certainly known to exist, e.g. Gleditsch, 2007; Buhaug & Gleditsch, 2008) and other unobserved heterogeneities cannot be accounted for either.

The analysis was performed using the statistical systems STATA (StataCorp, 2007) and R (R Development Core Team, 2007), the latter in combination with a number of specialized packages.<sup>5</sup>

# **4.0 Analysis and results**

The core set of explanatory variables included in the models is determined firstly by standard predictors of conflict commonly used in the literature, and is largely identical with those in Urdal (2006). We principally use the infant mortality rate (IMR) as the indicator of ‘general development’ in the present analysis, a measure that is both more sensitive to social development beyond material living conditions, and also more sensitive to economic inequalities. GDP per capita is used as an alternative measure to compare results with the seminal study of education and conflict by Thyne (2006). Two different measures of age composition are tested. Measure 1 is the ratio of males 15-24 to the male adult population 15+. This is consistent with the definition previously used. Measure 2, RYCS, is the ratio of males 15-29 to males 30-45, in a slight variation on the measure proposed by Staveteig (2004). The rationale is that this last measure is easy to interpret, namely the increase in young men 15-29 relative to their number 15 years earlier (ignoring mortality, which at these ages is normally fairly low).

Secondary education is found to provide the most suitable discriminator in assessing the role of education. Especially in later years, the proportion of the highest and lowest categories (completed tertiary and no schooling) are small in most countries, while the share of secondary educated youth covers the full range of possible values. Lastly, the measure is theoretically attractive and of particular policy importance. The transition to secondary-level qualification is a threshold for participation in the modern economic sector and as such is likely to mark a significant rise in opportunity costs for participation in violent conflict.

In addition, the effects of secondary schooling are of practical interest for policy formulation in developing countries. While the aim of universal primary schooling is considered a given since the Education for All (EFA) and Millennium Development Goals (MDG) processes, and for many developing countries mass participation at the tertiary level remains in any case far off, there is genuine debate and a wide range of opinions (both within developing countries and international organizations) regarding the appropriate rate of expansion of secondary schooling (Alvarez et al., 2003).

Finally, the use of secondary education or higher in the age group 20-24 helps reduce endogeneity and to disambiguate the direction of causation. Since secondary education is typically obtained at ages 15-19, its spread in the 20-24 age group depends on _past_ education trends, and cannot, therefore, be directly influenced by the occurrence of conflict in the year of analysis, only the reverse. The possibility that an unknown third factor affects both education and the occurrence of conflict, but with different time lags, can of course not be excluded.

> 5 Cranmer, 2007; Imai, King & Lau, 2007; 2008a; 2008b.

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