A negative effect of the discovery of petroleum on the Nigerian economy is

Step 1: Analyze the question The question asks for a negative effect of discovering petroleum on Nigeria's economy. So we must pick the option that describes a harm or disadvantage, not a benefit.

Step 2: Explain the concept Nigeria's oil boom of the 1970s led to what economists call "Dutch Disease" or over-dependence on a single resource. Before oil, Nigeria earned foreign exchange from agriculture: cocoa (West), groundnuts (North), palm oil (East), rubber, and cotton. After oil, government attention, investment and foreign exchange earnings shifted heavily to petroleum. Agriculture was neglected, and oil came to account for the vast majority of export earnings and government revenue.

Step 3: Evaluate each option

• A. Conversion of the economy into a mono-product type: Negative. The economy came to rely on one product (crude oil), making it vulnerable to price shocks, as seen when oil prices fell in the 1980s, 2014 and 2020.
• B. Development of infrastructures: Positive. Oil revenue helped fund roads, ports and similar projects.
• C. Encouragement of international recognition: Positive. Nigeria joined OPEC and gained global prominence.
• D. Provision of job opportunities: Positive. The oil sector and related services created jobs.
• E. Rapid industrialization: Positive (and arguably not fully achieved).

Step 4: Answer Only option A describes a disadvantage. Over-reliance on one commodity exposes the economy to external shocks and discourages diversification.

Exam tip: When a question says "negative effect" or "disadvantage," eliminate all the options that sound like benefits first. Remember the link: oil boom → agriculture neglected → mono-product economy.