Answer:
The statement that is not an effect of urban sprawl is the third, Crime rates in densely-populated areas drop.
Step-by-step explanation:
There are no data that correlates urban sprawling and crime rate's decrease.
All other statements, in the other hand, are explicit effects of urban sprawling: because new areas are becoming urbanized public services are demanded and tax revenues increases.
The public power has to build a whole new infrastructure to attend the necessities of the people who are moving to these spaces such as schools, housing, transportation, railroads etc.