Voting and Peer Effects: Experimental Evidence from Mozambique*

Voter education campaigns often aim to increase voter particpation and political accountability. We follow randomized interventions implemented nationwide during the 2009 Mozambican elections using a free newspaper, leaflets, and text messaging. We investigate whether treatment effects were transmitted through social networks (kinship and chatting) and geographical proximity. For individuals personally targeted by the campaign, we estimate the reinforcement effect of proximity to other targeted individuals. For untargeted individuals, we estimate the diffusion of the campaign depending on a proximity to targeted individuals. We find evidence for both effects, similar across the different treatments and across the different connectedness measures. We observe that the treatments worked through the networks by raising the levels of information and interest about the election, in line with the average treatment effects of voter education on voter participation. We interpret this result as a free riding effect, likely to occur for costly actionsInternational Growth Centre, Foundation Open Society Institut

experimental evidence from Mozambique

Voter education campaigns often aim to increase voter participation and political accountability. Randomized interventions were implemented nationwide during the 2009 Mozambican elections using leaáets, text messaging, and a free newspaper. We study the local peer e§ecs triggered by the campaign. We investigate whether treatment e§ects are transmitted through social networks and geographical proximity at the village level. For individuals personally targeted by the campaign, we estimate the reinforcement e§ect of proximity to other individuals in our sample. For untargeted individuals, we estimate how the campaign di§uses as a function of proximity to others in the sample. We Önd evidence for both e§ects, similar across treatments and proximity measures. The campaign raises the level of interest in the election through networks, in line with the average treatment e§ect. However, we Önd a negative network e§ect of the treatment on voter participation, implying that the positive e§ect of treatment on more central individuals is smaller. We interpret this result as consistent with free-riding through pivotal reasoning and we provide additional evidence to support this claim.authorsversionpublishe

Intraspecific leaf trait variability along a boreal-to-tropical community diversity gradient

Disentangling the mechanisms that shape community assembly across diversity gradients is a central matter in ecology. While many studies have explored community assembly through species average trait values, there is a growing understanding that intraspecific trait variation (ITV) can also play a critical role in species coexistence. Classic biodiversity theory hypothesizes that higher diversity at species-rich sites can arise from narrower niches relative to species-poor sites, which would be reflected in reduced ITV as species richness increases. To explore how ITV in woody plant communities changes with species richness, we compiled leaf trait data (leaf size and specific leaf area) in a total of 521 woody plant species from 21 forest communities that differed dramatically in species richness, ranging from boreal to tropical rainforests. At each forest, we assessed ITV as an estimate of species niche breadth and we quantified the degree of trait overlap among co-occurring species as a measure of species functional similarity. We found ITV was relatively invariant across the species richness gradient. In addition, we found that species functional similarity increased with diversity. Contrary to the expectation from classic biodiversity theory, our results rather suggest that neutral processes or equalizing mechanisms can be acting as potential drivers shaping community assembly in hyperdiverse forests.Leaf data used to come to this manuscript resulted from many different studies involving different funding sources: European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 265171; Spanish-funded project REMEDINAL3eCM (S2013/MAE-2719); Ecometas excellence network (CGL2014-53840-REDT); a FPU grant by the Spanish Government (AP2010-5600); a Marie Curie IEF fellowship (FP7-PEOPLE-2011-IEF. no. 302445);Peer Reviewe

DataSheet_1_Evolutionary lability underlies drought adaptation of Australian shrubs along aridity gradients.docx

Leaf drought tolerance traits influence plant survival in water deficit conditions, and these traits are influenced by both the plant’s evolutionary history and the environment in which the plant is currently growing. However, due to the substantial phenotypic plasticity in leaf traits, we still do not know to what degree variation in leaf traits is governed by species’ phylogenetic history or by their environment. To explore this question, we re-examined a drought tolerance dataset from 37 native Australian shrub species with varying climate origins growing in a common garden located in Melbourne, Australia. We previously measured seven leaf morphophysiological traits, and here, we estimated how phylogenetically conserved these traits are. We quantified phylogeny and the strength of correlation between the morphological traits and physiological traits before and after accounting for shared phylogenetic history. We also evaluated the relationship between species’ leaf traits and the climate of their native ranges. We present three main findings: (a) most leaf drought tolerance traits had weak phylogenetic signals, which is consistent with the convergent evolution of these traits. (b) There is weak but consistent coordination between distinct leaf drought tolerance traits, which can be masked due to species’ phylogenetic histories. (c) Leaf drought tolerance traits show strong correlations with the climate of species’ origins, and this relationship is only weakly impacted by phylogenetic signals. Therefore, the role of phylogeny on the coordination among leaf functional traits and their links to climate were limited. A better understanding of trait–environment relationships might be more pivotal than understanding the evolution of these traits for improving the predictions of species’ response to climate change–type drought, especially for shrub species that span substantial aridity gradients.</p

Summary table of the GLMM testing the change in the extent of ITV with species richness (SR), mean annual temperature (Mean.

<p>Ann. T^ra) and annual precipitation (Pp) for both leaf size and SLA.</p

Description of each forest community included in the study.

<p>Description of each forest community included in the study.</p

Intraspecific leaf trait variability along a boreal-to-tropical community diversity gradient - Fig 3

<p><b>Linear regression models of the median values of trait overlap (panel A, B) and the proportion of low (less than 0.25; panel C, D) and high (> 0.75; panel E, F) values of degree of trait overlap between species for each forest community against species richness for both leaf size (left) and SLA (right).</b> Trait similarity was calculated by assuming normal trait distribution of species with ≥ 5 individuals measured. (***): p-value <0.001; (**): p-value <0.01; (*): p-value < 0.05; (.): p-value <0.1.</p

Intraspecific leaf trait variability along a boreal-to-tropical community diversity gradient - Fig 2

<p><b>Effect of species richness on the extent of ITV (estimated as coefficient of variation, CV) for (A) leaf size and (B) SLA.</b> n = number of species measured for each forest community with ≥ 5 individuals measured. Empty circles indicate the average of ITV values for each forest community and richness level. The number of sampled species (n) may be both lower than the species richness of the community since we sub-sampled a forest layer, but also, potentially larger than the species richness of that community since the arrival of seeds from neighbor canopies may result in the establishment of new individuals that previously were not part of the main canopy of the focal community.</p