The article explores how individuals make investment decisions and negotiate deals with each other over multiple rounds. They found that stable rules for fair negotiations can exist, regardless of the initial investment choices made. These rules ensure that future trading possibilities influence current bargaining more than having an alternative option. When investments can be substitutes, fair rules lead to higher incentives for investing, while when they are complements, fair rules result in lower incentives. If trading isn't efficient due to an outside option and investments are complements, no stable rules for fair bargaining can develop, leading to typically inefficient investment levels.