The private value of lawsuits is based on plaintiffs' expected recovery at trial compared to their filing costs, whereas the social value consists of the incentives suits create for injurers to invest in accident avoidance. Generally, there is no relationship between these two values: there may be either too many or too few suits from a social perspective. Thus, there is scope for corrective measures, although there is no simple policy. Extending the model to consider a negligence rule rather than strict liability, and to allow for pretrial settlements, leads to some modified conclusions but does not alter the basic insights.
Miceli, Thomas J., "The Social versus Private Incentive to Sue" (2008). Economics Working Papers. Paper 200812.