Assessing Substitution and Complementary Effects Amongst Crime Typologies

This paper aims at assessing how offenders allocate their effort amongst several types of crime. Specifically, complementary and substitution effects are investigated amongst the number of recorded homicides, robberies, extortions and kidnapping, receiving stolen goods, falsity and drug-related crimes. Furthermore, the extent to which crime is detrimental for economic growth is also analysed. The case-study country is Italy, and the time span under analysis is from the first quarter of 1981 to the fourth quarter of 2004. A Vector Error Correction Mechanism (VECM) is employed after having assessed the integration and cointegration status of the variables under investigation. Empirical findings show that, in the long run, an increase in the overall welfare has a negative impact on the most serious crimes. In addition, the long-run elasticities reveal symmetric results in terms of positive and negative relationships amongst types of crime. In the short run, the cross-deterrence elasticities highlight a complementary effect between more serious crimes (i.e. robberies, extortions and kidnapping) and milder crimes (i.e. drug-related crimes and falsity) and a substitution effect amongst all other types of offences. Policy implications are drawn.     

Bionomics of two forensically important blowfly species Chrysomya megacephala and Chrysomya putoria (Diptera: Calliphoridae) reared on four types of diet

The use of heterogeneous animal tissues for the rearing of necrophagous insect species can produce uneven biological data, which can compromise the determination of larval age and, consequently, estimates for post-mortem intervals. We investigated the development of two species, Chrysomya megacephala and Chrysomya putoria (Diptera: Calliphoridae), reared on four substrates: minced beef (control) and semi-synthetic diets with the addition of sardine, rumen or chicken eggs. No differences in total developmental times were detected among larvae reared on different diets. Length and width of larvae were partially affected by the type of food. Third instar larvae and pupae of both species were heavier on beef treatment when compared with other substrates. Overall mortality was lower when beef was used as food. Longevity of adults and sex ratio were not negatively affected by the use of diets. Egg-based diet was the least effective for both species. Given the fact that several bionomical parameters of larvae reared on diets were close to those obtained when minced beef was offered, and considering the putrid odour, frequency of contamination and lack of homogeneity of animal tissue, semi-synthetic diets can be used for rearing C. megacephala and C. putoria.