Debtors' prison is a prison for people who are unable to pay debt. As recently as the mid 19th century, it was a common way to deal with unpaid debt in Western Europe. Debtors' prison started to disappear since the start of the 20th century. Today, none of the major economies practise it anymore.
What were the factors that caused debtors' prison to disappear in most parts of the world in the 20th century?