Final answer:
Changes in drug markets and improved security technology are believed to be major factors contributing to the increase in robbery rates and the decrease in burglary rates during the 1980s. The rise of organized drug trafficking networks led to more robberies, while advancements in security made burglaries less common.
Step-by-step explanation:
The divergence in rates of robbery and burglary starting in the 1980s can be attributed to several factors. One such factor is changes in drug markets (B), which profoundly affected crime rates. During this period, the rise of powerful drug networks, often tied to street gangs, led to an increase in violent crime due to rivalries and the necessity to protect drug territories. These networks were heavily involved in robbery as a means to fund their activities or as part of territorial disputes. On the other hand, improved security technology (C) may have contributed to the decrease in burglary, as advancements such as better locks, alarm systems, and increased use of surveillance cameras made burglaries more challenging and risky. Other factors, including social economic aspects like poverty, gang activity, and demographic factors like residential mobility and ethnic heterogeneity, are also important in determining crime rates.