Your question is rather ambiguous because of your choice of the preposition "on": "effects on overpopulation." If you had said "of" overpopulation, the answer would include ways that overpopulation (having too many people in a region, country or the world) changes social and economic situations and circumstances. One social effect OF overpopulation is pressure between peoples that result in wars (e.g., war in Darfur) as they compete for precious life-sustaining resources like drinking water. An economic effect OF overpopulation is an increasing cost of living as resources, especially housing and food, become more scarce and more people go without these basic needs (or live in shanty towns built of corrugated board and other scrap material).
If, on the other hand, you actually mean "effects on overpopulation," then your question can be understood to mean "social and economic effects producing overpopulation." This is a very different question and has a very different answer since it is asking, in essence, "What causes overpopulation?" One social effect ON, or social cause for overpopulation is that medical advancements have increased survival rates: infants don't die as often as in previous centuries; adults don't die of infectious diseases as often as before the 20th century; mothers don't die in childbirth as frequently as they once did. One economic effect ON, or economic cause for overpopulation is increased wealth in newly powerful middle classes in countries around the world, often with earnings protected by unions and by pro-worker laws; increased wealth feeds and gives medical care to more family members so that more individuals survive and thrive on the new economic disbursal of wealth.
Human overpopulation can have a huge and long-term social and economic impact. Listed are some social and economic effects that occur as result of overpopulation.
- Physical and mental damages to individuals, which negatively affects society.
- Overpopulation can cause a delay in providing proper medical treatment.
- Elevation of racial tensions.
- Increase of crime due to competition for employment resources, especially minimum wage jobs.
- Declining neighborhoods because of lack of money to maintain and repair housing.
- Increased risk of greater numbers of single mothers and inadequately provided for children in poor neighborhoods.
- An increase in the cost of living because of the potential lack of affordable housing options, limited transportation options, and food supply.
- Overpopulation increases the competitive job market race for employment opportunities in all professionals from minimum wage to executive level positions.
- Price increase for oil demand because of lack of natural resources.
- Increase in property taxes by the local government to offset property taxes not received from abandoned properties or unpaid property taxes by homeowners.
- Increase in costs associated to maintain jails and prisons due to the potential increase of the prison population due to lack of access to sustainable jobs.