16. Why might you need to consider consumption allocations within the household? Give an example to illustrate your answer. 17. Why might differences in the food share (the share of the budget devoted to food) between different dates or different locations be deceptive for drawing conclusions about welfare? 18. What are the advantages and the potential problems in using self-assessments of welfare in measuring poverty? 19. What are the arguments against using a poverty line to measure poverty? 20. What methods are used to update poverty lines over time? How might biases in a country's CPI affect the poverty rate? 21. What is the relationship between the Gini index and the Lorenz curve? How is the Lorenz curve constructed? 22. Suppose that all incomes in a country rise by the same proportion. How does this change the Lorenz curve?