The term "disposable income" conceptually represents "net pay" (or "income received"), and in practice, it refers to "net income based on total income minus social insurance contributions and income taxes." A similar concept known as "discretionary income", on the other hand, refers to "disposable income" minus fixed expenses incurred in one's daily life, including interest payments on loans, social insurance premiums, taxes, fines, rent, and utilities. In other words, "discretionary income" is the net income after all obligatory payments have been deducted. These two measures of "net pay" are different in terms of scope and nature.

Looking at disposable income disparity from a gender perspective offers a glimpse into a country's gender equality in terms of cultural, social, or economic development. Furthermore, the female/male ratio for the disposable income of a country or economy provides information on women's role compared with men and the degree of women's participation in its economy. In terms of statistics, the higher the female/male ratio for disposable income, the closer women's disposable income is to that of men, which indicates a more balanced relationship between the two genders for this particular category of measuring equality. However, a lower female/male ratio indicates a lower level of women's disposable income relative to men.

The World Competitiveness Yearbook published by the International Institute for Management Development (IMD) in Lausanne, Switzerland, has been conducting, since 2013, the annual ranking of about 60 countries or economies based on their female/male ratios for disposable income. The yearbook provides interested parties with data relevant to research on the disposable income of women compared with men.

Based on IMD's latest (2021) data, the ten countries with the highest female/male ratios for disposable income are all located in Europe. In contrast, Asian nations, especially some in the Middle East, rank relatively low in the list, which indicates that the gender ratio for disposable income is somewhat correlated with a country's geographic location, national character, and economic development. The results of the evaluation place Belgium at the top of the list with 94.93%, followed by Sweden (89.66%), Switzerland (89.49%), Norway (86.99%), Lithuania (86.65%), Latvia (85.84%), Germany (85.05%), Hungary (84.92%), the United Kingdom (84.47%) and Finland (84.07%).

Taiwan ranks 22nd globally with a score of 79.07%, which is ahead of the following Asian countries and economies: Hong Kong (26th, 77.49%), Singapore (27th, 76.45%), Japan (42nd, 67.46%), China (48th, 62.69%), and South Korea (51th, 62.16%).

The bottom three countries on the list have a female/male ratio for disposable income below 30%: India (24.44%), Saudi Arabia (19.41%), and Jordan (15.62%).