provisions (Brady Campaign, 2002). State laws differ in what age children are covered, ranging from 12 to 18, in the penalty imposed, from civil to criminal liability, and what it means to safely store a gun. Effectively, however, CAP laws require gun owners with children to lock their firearms.
Two papers evaluate the effects of CAP laws on accidents, suicide, and crime. Lott and Whitley (2002), using the same basic data and methods as in the Lott and Mustard (1997) analysis of right-to-carry laws (see Chapter 6), conclude that CAP laws have no discernible effect on juvenile accidents or suicide, but they do result in a substantial increase in violent and property crime. In sharp contrast, Cummings et al. (1997) find that CAP laws reduce accidents and may reduce suicide and homicide among youth as well, although these are imprecisely estimated.5 They conclude that during the five-year period from 1990 to 1994, these statutes prevented approximately 39 deaths of young children, and another 216 children might have lived had these laws been in effect in all states.
It is difficult to explain the conflicting estimates. Using state-level injury statistics, both analyses rely on interrupted-time-series designs that assume, after controlling for observed factors, that CAP laws were the only notable change in the environment. The formal models and specifications differ. Cummings et al. (1997) estimates a negative binomial count model with fixed state and time effects but an otherwise parsimonious specification of control variables. Lott and Whitley (2002) use Tobit and log-linear models with fixed state and time effects and a rich specification of 36 control variables to account for variation in demographics (e.g., age, race, income, education) and firearms laws. Lott and Whitley also evaluate different outcomes and assess the sensitivity of their findings more generally.
In both studies, it is unreasonable to assume that CAP laws were the only notable event that may have affected firearms related injury and crime. Time-series variation in crime is thought to be a highly complex process that depends on numerous economic, demographic, and social factors. Moreover, CAP laws and other local firearms legislation may be adopted in response to the local variation in the outcomes of interest. For example, a sharp increase in accidental injuries and fatalities spurred a Florida legislature that had previously turned down similar legislation to adopt the CAP law in 1989 (Morgan, 1989). If the 1988-1989 wave of accidental injuries would have naturally regressed back to some steady-state level, any observed correlations between Florida’s CAP law and the injury rate would be spurious. Even if all the other factors that may influence injury or crime are time invariant, the dynamics that connect the law to the outcomes of inter-