Final answer:
The result of OPEC overproduction in 1986 was a significant decrease in oil prices due to a surplus in the global market and diminished ability of OPEC to control production quotas among its members.
Step-by-step explanation:
In 1986, the result of OPEC overproduction was a significant drop in the price of oil. OPEC, the Organization of Petroleum Exporting Countries, which was established in the 1960s to regulate the global oil market, faced challenges in dictating production quotas to its members in the 1980s. After a period of restrictions, the increased oil production led to a surplus in the global market. This destabilized oil prices, causing them to drop significantly from the artificial highs maintained after the 1973 oil embargo. This price drop was further influenced by the end of the Cold War, which promoted freer trade and contributed to the instability of OPEC's pricing power.