Self-enforcing norms and efficient non-cooperative collective action in the provision of public goods

We show how norms can solve the distributional conflict inside a group in an anarchic environment and yield efficient coordination of collective action in a conflict with an external competitor. The equilibrium of the fully non-cooperative game with finite horizon has two interesting features. First, one of the players assumes a central role that resembles the role of the ??big-man?? in some primitive stateless societies. Second, the group members?? contributions to collective output and the payments from the big-man to these members seemingly look like reciprocal behavior, even though they are driven by narrowly selfish preferences.     

Buying supermajorities in a stochastic environment

This paper considers a model in which two opposing lobbyists compete for the votes of legislators, but the precise preferences of the legislators are not known. I show that, in contrast to the normally predicted effect of uncertainty on the formation of supermajorities, in the presence of competing lobbyists, increased risk that members of a lobbyist’s coalition will not vote for the proposal may decrease the number of legislators a lobbyist includes in her coalition.     

Let's stick together: Understanding Africa's secessionist deficit

Over the last 40 years, Africa has experienced relatively fewersecessionist conflicts than most other regions of the world,even though it is otherwise plagued with political violenceand its countries tend to display a higher prevalence of manyof the factors usually associated with separatism. After empiricallyestablishing Africa’s secessionist deficit, this articlereviews the few existing explanations for it before articulatinga theory which singles out the benefits to African regionalelites (and those who depend on them) of weak sovereign states.In Africa as elsewhere, the article argues, regional leaderscan be expected to capitalize on local grievances and promotesecessions if the potential rewards of a separatist state, inthe absence of international recognition, outweigh the potentialrewards associated with control or partial control of institutionsof the sovereign national state. What distinguishes Africanelites is the relatively greater material returns to sovereigntythat they face. Given the continent’s poverty, the undiversifiednature and commodity dependence of its economies, and the relativelack of accountability of state power, Africa offers a significantmaterial premium to internationally recognized sovereignty,tilting the odds for elites in favour of staying within thestate, even if they do not immediately benefit from power atthe centre. The article then tests the argument against actualAfrican cases of secession, showing that they are usually afunction of variations in the relative rewards of sovereignty.In conclusion, it argues that Africa’s weak sovereigntyequilibrium has contributed to its failure to develop.     

"Advantages" of exclusion probability in blood group evaluation?

There is no apparent advantage in using exclusion probability A (or WA) in cases where parentage is disputed in either normal or special cases. Furthermore, WA provides no more information than WEM. However, the converse is true: WA does not take the serotype of the putative father into account. Moreover, it is neither easier to understand nor easier to work with and, like WEM, it also requires a prior probability. WA is also not helpful in interpreting WEM; for this, one has to use mean WEM values for fathers and non-fathers. There is no reason to expect WA and WEM to converge at the upper end of the scale. WA is unsuitable for establishing the borderline where decisions may no longer be valid, as the error quota in individual cases can be greater than that allowed within the limits. 100-WEM % is the probability or error in categorical decisions in 100 cases with similar combinations. In contrast, 100-WA % cannot provide a reliable probability of error in individual cases because WA does not take full account of the phenotype of the putative father.