Sharp bounds on sufficient-cause interactions under the assumption of no redundancy

BACKGROUND: Sufficient-cause interaction is a type of interaction that has received much attention recently. The sufficient component cause model on which the sufficient-cause interaction is based is however a non-identifiable model. Estimating the interaction parameters from the model is mathematically impossible. METHODS: In this paper, I derive bounding formulae for sufficient-cause interactions under the assumption of no redundancy. RESULTS: Two real data sets are used to demonstrate the method (R codes provided). The proposed bounds are sharp and sharper than previous bounds. CONCLUSIONS: Sufficient-cause interactions can be quantified by setting bounds on them. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12874-017-0348-y) contains supplementary material, which is available to authorized users.