Broken Window theory - Wilson
Wilson - uses the phrase 'broken windows' to stand for all various signs of disorder & lack of concern for others that are found in some neighbourhoods, includes undue noise, graffiti, littering, begging etc.
Wilson argues that leaving broken windows unrepaired, tolerating aggressive behaviour etc, sends out a signal that no one cares.
In these neighbourhoods, there is an absence of both formal and informal social control.
The situation deteriorates 'tipping' the neighbourhood into a spiral of decline. Respectable people move out and the area becomes a magnet for deviants.
Wilson argues in favour of harsher prison sentences as a solution.