system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 what is a country's economy, and how or when does it collapse?
gpt
The economy is the sum total of all goods produced, bought, and sold within a country. It is typically measured using an index called the "Gross Domestic Product," which is the total value of goods sold in that country in a given year. 

An economic collapse can mean many things. It can mean a significant drop in GDP (Economists say that two consecutive quarters with a shrinking GDP constitutes an economic recession.) It can mean a spike in unemployment. It can mean a significant drop in the value of the country's currency.

As to why an economy collapses - many reasons. Droughts, wars, out of control real estate speculation, revolutions, global pandemics...