Ignorance is a bliss: mathematical structure of many-box models
  We show that the propositional system of a many-box model is always a set-representable effect algebra. In particular cases of 2-box and 1-box models it is an orthomodular poset and an orthomodular lattice respectively. We discuss the relation of the obtained results with the so-called Local Orthogonality principle. We argue that non-classical properties of box models are the result of a dual enrichment of the set of states caused by the impoverishment of the set of propositions. On the other hand, quantum mechanical models always have more propositions as well as more states than the classical ones. Consequently, we show that the box models cannot be considered as generalizations of quantum mechanical models and seeking for additional principles that could allow to "recover quantum correlations" in box models is, at least from the fundamental point of view, pointless. 
Tomasz I. Tylec and Marek Ku\'s
quant-ph