Often, income based household data was used in one year but in the next, household net expenditure would be used to calculate measures of inequality resulting in important fluctuations in within country inequality measures across time, show how measures based on household gross income tend to be systematically larger than those measured on household net expenditure. It is in this context that the results are to be interpreted. Nevertheless, recent work by the OECD (2011, p22) suggests that wages and salaries account for 75% of household incomes among working-age adults and, therefore, that increases in household income inequality may have largely been driven by changes in the distribution of salaries.33 Additionally, working with wage data also provides a better link with the theoretical literature on the impact of value chain trade and inequality which makes predictions related to changes in wages.