Petroleum has the following positive contributions to the Nigerian economy except

Step 1: Analyze the question The question asks for the option that is NOT a positive contribution of petroleum to the Nigerian economy. This is an "except" question, so three options are benefits and one is a drawback.

Step 2: Explain the concept Petroleum (crude oil) is Nigeria's biggest source of foreign exchange and government revenue. Its main positive contributions include:

• Employment for Nigerians in oil companies, service firms and related industries
• Government revenue from royalties, taxes and the sale of crude oil
• Foreign exchange earnings
• Infrastructure development, as oil revenue funds roads, power, schools and hospitals
• Growth of linked industries, such as refining, petrochemicals and transport

A mono economy is one that depends heavily on a single product for most of its income and exports. Nigeria's over-dependence on oil is a well-known problem. When oil prices fall, government revenue collapses, as happened in 2015 and 2016. This is why economists urge diversification into agriculture, manufacturing and services.

Step 3: Test each option

• A. Generate employment: a positive contribution.
• B. Source of government revenue: a positive contribution, since oil provides the majority of federal revenue.
• C. Development of a mono economy: a negative effect. It makes the economy vulnerable and neglects other sectors.
• D. Infrastructure development: a positive contribution.

Step 4: Answer The option that is not a positive contribution is C. Development of mono economy.

Exam tip: In "except" questions, look for the option that points to a problem, such as dependence, vulnerability or neglect of other sectors. Words like "mono-economy", "over-dependence" and "Dutch disease" usually signal a negative effect in Nigerian economics questions.