Which theory served as the basis for new policing strategies in the late 1980s and 1990s that aggressively focused on minor crimes such as traffic violations and drinking or using drugs in public?

 the "broken-window theory" .

In financial aspects, a depression is a sustained, long haul downturn in monetary movement in one or more economies. it is a more extreme monetary downturn than a recession, which is a slowdown in financial action through the span of a typical business cycle. a depression is an irregular and extreme type of recession. so depression is always followed by recession but it is not correct to state that a depression always follow a recession.