The data included in the analysis draw upon interviews with 719 lawyers involved in 564 cases. Each lawyer was asked to estimate the number of hours spent working on the case and to indicate how the time was allocated among different litigation activities. A model of the time investment process was constructed. As the dependent variable, the model used the total number of hours each lawyer's firm or office spent on the case. The independent variables were the characteristics of the case, the events that occurred, the nature of the participants, the goals of the participants, and the way the case was processed and managed. To assess the relationship between costs and benefits for plaintiffs, two measures were used: the ratio of recovery to fees and the ratio of net recovery to stakes. By and large, plaintiffs were found to recover more than they invested in litigation, with 'success' being more likely for recoveries over $10,000. The defendant's benefits were measured by reduction of a potential cost which could have been incurred without litigation. About 25 percent of the defendants who invested in litigation were successful by this measure. For both plaintiffs and defendants, the costs of litigation are relatively higher in the smaller cases. Since the data indicate that most cases in U.S. civil courts involve stakes and recoveries of less than $10,000, there is cause for concern about the costs of litigation. Twenty-seven references are provided; the appendixes present details of methodology and findings. For related material, see NCJ-90435.