Capitalizing on the mobility of livestock is one of the major ways in which pastoralists have managed ecological uncertainties and risks, as it enables them the opportunistic use of the resources. However, agricultural encroachment onto rangelands by nearby agro-pastoralists has led to a shortage in grazing area and threatened the mobility of the pastoralists. As this process leads to a significant disruption and weakening of the risk-management systems of pastoralists, they seek for various institutional arrangements with agropastoralists to enable them access to common grazing land. Based on an exploratory survey and data derived from interview of 146 households in ea stern Ethiopia, this paper uses an adaptation of the sequential rationality game theoretical model and institutional analysis to discrete choice models. The analytical framework, in its entirety, presents a simple model of household and community level decision-making, in which they are concerned about t heir welfare along many different dimensions. Choice of institutional arrangement, namely no opinion, reciprocal, sharing milk and the right to use milk, is modelled using multinomial logit discrete choice procedure. The model chi-squared statistic is significant at the 1% level of probability. For all arrangements, there are three to five observable characteristics of household that provide statistically significant predictive power for practicing a given arrangement. The paper argues resource scarcity may enhance the bargaining position of asset-poor members of an agro-pastoral society and urges the wealthier agropastoralists to comply with a non-violent resolution of competing claims towards a resource sharing arrangement.