How Deliberation Changes Policy Attitudes: Learning versus Diversity

Deliberation often changes policy attitudes. But how? It may be that they learn more about the issues. Or that they confront uncongenial facts, countervailing arguments, and people unlike themselves (all rare experiences in everyday life). Here we weigh these two possibilities. We take our data from Europolis, a 2009 pan-EU Deliberative Poll (DP), an admittedly special but interesting case. A probability sample of all the (then 27) member states deliberated for a weekend in nationally mixed groups—becoming somewhat more open to immigration and slightly more inclined to take action against climate change. We estimate these attitudes’ dependence on underlying values (economic conservatism and environmentalism with respect to climate change and economic conservatism and traditionalism with respect to immigration)—as well as those effects’ dependence in turn on the individual’s learning (knowledge gain), his or her mean (attitudinal or demographic) distance from his or her discussion partners, and the latter’s (attitudinal or demographic) heterogeneity. These last variables are both aspects of “diversity.” The deliberation in a DP produces widespread knowledge gains, increases most individuals’ distance from their discussion partners (who are randomly assigned, here within nationality) and, for most individuals, also makes those discussion partners more heterogeneous. We examine the role that each of these three departures (knowledge, distance, heterogeneity) from every life plays in the deliberators’ changes of attitude. Based our estimations, we simulate the attitudes corresponding to much higher than real-world levels of knowledge and much lower than DP levels (something like back-home levels) of distance from discussion partners and discussion partners’ heterogeneity.