(NVDRS) indicates that reporting of mortality due to firearms has overestimated the age of victims; such victims are actually younger than previously estimated. This can have a profound effect in calculating long-term costs (especially productivity and social losses).
A few issues on the actual accounting of costs were also raised. Dr. Corso asked how pain and suffering are quantified. Ms. Tomaszewski suggested that including community costs, not just aggregated individual costs, is important as well. Dr. Waters pointed out that aggregating numbers can often yield huge ranges, because each individual cost is often displayed as a range. He also noted, and was echoed by speaker and Forum member Rodrigo Guerrero of Cali, Colombia, that these large ranges are not always helpful to policy makers. Likewise, traditional economic approaches to measuring costs can result in confusion, such as the determination of the discount rate—the deduction applied to the future value of money so as to make comparisons to current value. The discount rate can vary by region, year, time line of projection, and economic model, yielding large intervals in value. The mathematical models often used for calculating costs rely heavily on theoretical assumptions that might not always be valid—for example, models incorporating counterfactual worlds in which violence does not exist can never be assessed for accuracy.
Speakers also questioned the presentation of cost data. Often such numbers are presented in terms of dollars lost or as a percentage of the gross domestic product (GDP). The first has the disadvantage of providing less meaningful comparison across countries, and the second is often confusing to those outside of economics. The importance of context-specific denominators for such numbers is essential in showing true impact but can hamper generalizability and comparison.
Both Ms. Tomaszewski and Dr. Prothrow-Stith commented on measuring externalities such as historical trauma and discrimination. Dr. Prothrow-Stith also questioned the possibility of measuring fear and its effect on behavior, which could have enormous implications for longer-term outcomes such as chronic health effects and future perpetration of violence. Dr. Betancourt mentioned the impact of collective violence on non-state actors and infrastructure, causing widespread damage that often takes years to address. Such impact can serve as a risk factor for future violence, again bringing forth the question of measuring the cost of future violence.
Finally, some speakers questioned the negative costs of some measures of prevention that are deemed effective. In particular, Dr. Phillips and Dr. Hemenway pointed out that access to dangerous weapons is a risk factor that can be addressed by legislation, but has implications of restricting freedom in the U.S. political climate. If costs can be calculated based on what society is willing to pay to prevent such violence, certain preventive interventions will always be deemed as having too high a cost.