Household debt has been rising in many countries, and this study looked at why. They considered four reasons: people spending more to keep up with others, rising property prices leading to more spending and borrowing, low interest rates encouraging borrowing, and credit market deregulation making it easier to borrow. The study found that high real estate prices were the main reason for increased household debt, suggesting speculation in the housing market. Income inequality did not have a significant impact on household debt. Low interest rates and credit deregulation did play a role, but were not as important during the 1995-2007 period.