While previous research found no other variable than corruption to have a negative impact on (the growth rate of) the African countries' elephant populations, we show that one further significant impact is exerted by what one might call neighbourhood effects. Elephants travel long distances, often crossing borders. Using spatial econometric tools, we find that elephant population changes in one country ...
Design-based estimators of totals, means or proportions in finite populations generally are functions of weighted sums. If each element selected into the sample is also observed, then for the calculation of the pi-estimator these weights are just the inverse inclusion probabilities of the elements. However, if e.g. nonresponse or attrition over time occurs, calculation of these weights also includes ...