Transaction cost economics (TCE) theorists traditionally have classified transactions between firms as governed by either market or hierarchy. By assessing characteristics of the transaction - asset specificity, uncertainty, and frequency - firms choose the governance form which minimizes transaction costs, the costs of administering the business deal. During the 1980s, however, TCE has found itself unable to explain the proliferation of strategic alliances. These hybrid relationships seek the benefits of both markets and hierarchies, including quasi-integration, the control of assets without actual ownership. Further, hybrids tend to prefer trust-based relational contracting. TCE's acknowledgment of hybrids, however, raises other questions surrounding the behavioral assumptions which supposedly influence the transaction characteristic governance linkage. Various dissenting researchers have theorized that (1) trust is more dominant in business than opportunism (2) the behavioral assumptions actually function as variables in different contexts, and (3) trust offers an integration mechanism for behavioral variables.