The Hadendowa Salif: Successes and failures of indigenous cultural institutions in managing the food system
The Hadendowa's customary law code, the Salif, used to regulate the social and economic behaviour of the Hadendowa, as well as their rational utilization of resources. Since the outbreak of the 1984 famine, however, the Hadendova have been depending on relief food, which has disrupted their Salif and rendered it uncapable of helping the Hadendowa to to cope with the current stress situation.
The responses of different ethnic groups in the Sudan to rural-urban migration
The ethnic identities of the various population groups in the Sudan are a product of their specific natural and social environments. The migration of these groups to the towns, especially to Greater Khartoum, involves a drastic change of cultural norms and values. However, the capability of change and the subsequent results are strongly conditioned by the specific background of each ethnic group and by the conditions in its area of origin. This is being proved by a comparative study on three ethnic groups in the Sudan: the Nuba, the Zaghawa and the Hadandawa.
When to Cross the Spread? Trading in Two-Sided Limit Order Books
In this paper the problem of optimal trading in illiquid markets is addressed when the deviations from a given stochastic target function describing, for instance, external aggregate client flow are penalized. Using techniques of singular stochastic control, we extend the results of [F. Naujokat and N. Westray, Math. Financ. Econ., 4 (2011), pp. 299--335] to a two-sided limit order market with temporary market impact and resilience, where the bid ask spread is now also controlled. In addition to using market orders, the trader can also submit orders to a dark pool. We first show existence and uniqueness of an optimal control. In a second step, a suitable version of the stochastic maximum principle is derived which yields a characterization of the optimal trading strategy in terms of a nonstandard coupled forward-backward stochastic differential equation (FBSDE). We show that the optimal control can be characterized via buy, sell, and no-trade regions. The new feature is that we now get a nondegenerate no-...