Cross-section and panel estimates of peer effects in early adolescent cannabis use: With a little help from my ‘friends once removed’

Peer effects in adolescent cannabis are difficult to estimate, due in part to the lack of appropriate data on behaviour and social ties. This paper exploits survey data that have many desirable properties and have not previously been used for this purpose. The data set, collected from teenagers in three annual waves from 2002-2004 contains longitudinal information about friendship networks within schools (N = 5,020). We exploit these data on network structure to estimate peer effects on adolescents from their nominated friends within school using two alternative approaches to identification. First, we present a cross-sectional instrumental variable (IV) estimate of peer effects that exploits network structure at the second degree, i.e. using information on friends of friends who are not themselves ego’s friends to instrument for the cannabis use of friends. Second, we present an individual fixed effects estimate of peer effects using the full longitudinal structure of the data. Both innovations allow a greater degree of control for correlated effects than is commonly the case in the substance-use peer effects literature, improving our chances of obtaining estimates of peer effects than can be plausibly interpreted as causal. Both estimates suggest positive peer effects of non-trivial magnitude, although the IV estimate is imprecise. Furthermore, when we specify identical models with behaviour and characteristics of randomly selected school peers in place of friends’, we find effectively zero effect from these ‘placebo’ peers, lending credence to our main estimates. We conclude that cross-sectional data can be used to estimate plausible positive peer effects on cannabis use where network structure information is available and appropriately exploited.

Lost and Found? A Parable of the Architect (Male) and the Academic (Female)

The following text captures an interview, conducted over three evenings, between a practicing architect (male) and an architecture academic (female and feminist). This is a conversation between two long-standing friends who did their Part 3 professional exam together more than twenty-five years ago. Since then, they have taken different career paths and lived lives at different paces and in different places. Every so often they meet over coffee to laugh and argue about architecture, bemoan failures, and share successes.

The academic initiated the interview in order to hear an honest and open account of the career experience of a male architect. She hoped that their longstanding friendship would lead to less guarded responses. The answers to the questions were always going to be personally challenging to the interviewer and possibly to their friendship. The interview is a form of ethnographic study: a structured, qualitative process within a long term, immersed context. But when ‘the immersed context’ is a much-valued friendship, it is a precarious action. Nevertheless, for the future of gendered relationships both protagonists accepted the risks.

Servius in the Carolingian Age: A Case Study of London, British Library, Harley 2782

In Harley 2782, Servius’s late antique commentary on Vergil was transmitted as an independent text, edited, corrected, glossed, marked for mythological information, provided with NOTA monograms and headings, as well as interspersed and augmented with scholia adespota and non-Servian material. The scholarly conventions attested in this manuscript show the kinds of critical apparatus that fed into the early medieval appropriation of Vergil and above all demonstrate that Servius was a staple of the Carolingian world.

Dans le manuscrit Harley 2782, le commentaire tardo-antique de Servius sur Virgile a été transmis sous forme d’un document indépendant, modifié, corrigé, glosé, préparé pour retrouver les informations mythologiques, enrichi de monogrammes Nota, ainsi qu’il a été entrecoupé et augmenté à l’aide des scholia adespota et du matériel non Servien. Les conventions scolastiques attestées par ce manuscrit montrent quels types d’apparats critiques alimentaient le début de l’appropriation médiévale de Virgile et surtout prouvent que Servius était une composante essentielle du monde carolingien.