Inflation is a term that refers to a general increase in prices and the lose of the purchasing value in money; it happens in most countries and it usually gets worse as time passes, meaning that buyers can buy less things with the same amount of money through different periods of time. Due to this, a product that was $3 dollars in 2013, could be more expensive as of today.
It would be less expensive to get things from Africa in 2013 than 2020 because certain resources are going to become more scarce over time bringing the prices up.
