The “trends in top incomes does not suggest that there has been a sustained long-term increase in income inequality in Indonesia”, Andrew Leigh and Pierre van der Eng conclude in a recent working paper.
In short, as Indonesia’s economy grows, the rich do get richer. But so do the poor.
Income Share of the Top 10% in Indonesia (Figure 2 in the paper)
Hence, in the last two decades, the income share of the 10 percent richest remains pretty much the same, in the 35%-40% range.