This dissertation examines how households manage their money over time, especially when they have limited funds. The author looks at how income changes affect spending habits, focusing on healthcare and food expenses. They found that when households are short on cash, they tend to spend less on healthcare now and in the future. The impact of money constraints on healthcare spending differs from other types of spending. Additionally, the relationship between income and healthcare spending varies between families with different levels of wealth. Overall, the effects of money constraints on spending habits vary among households and types of expenses.