Divide and choose  Divide and choose (also Cut and choose or I cut, you choose) is a procedure for envy-free cake-cutting between two partners. It involves a heterogeneous good or resource ("the cake") and two partners who have different preferences over parts of the cake. The protocol proceeds as follows: one person ("the cutter") cuts the cake into two pieces; the other person ("the chooser") chooses one of the pieces; the cutter receives the remaining piece. Divide and choose is mentioned in the Bible, in the Book of Genesis (chapter 13). When Abraham and Lot come to the land of Canaan, Abraham suggests that they divide it among them. Then Abraham, coming from the south, divides the land to a "left" (western) part and a "right" (eastern) part, and lets Lot choose. Lot chooses the eastern part which contains Sodom and Gomorrah, and Abraham is left with the western part which contains Beer Sheva, Hebron, Beit El, and Shechem. Divide and choose is envy-free in the following sense: each of the two partners can act in a way that guarantees that, according to their own subjective taste, their allocated share is at least as valuable as the other share, regardless of what the other partner does. Here is how each partner can act:  To an external viewer, the division might seem unfair, but to the two involved partners, the division is fair—no partner envies the other. If the value functions of the partners are additive functions, then divide and choose is also proportional in the following sense: each partner can act in a way that guarantees that their allocated share has a value of at least 1/2 of the total cake value. This is because, with additive valuations, every envy-free division is also proportional. The protocol works both for dividing a desirable resource (as in fair cake-cutting) and for dividing an undesirable resource (as in chore division). Divide and choose assumes that the parties have equal entitlements and wish to decide the division themselves or use mediation rather than arbitration. The goods are assumed to be divisible in any way, but each party may value the bits differently. The cutter has an incentive to divide as fairly as possible: if they do not, they will likely receive an undesirable portion. This rule is a concrete application of the veil of ignorance concept. The divide and choose method does not guarantee that each person gets exactly half the cake by their own valuations, and so is not an exact division.