Editing Income distribution (section)

=== Labor union ===
It is known that [[labor union]] reduces the income inequality in both private and public sectors, and research conducted by [[David Card]] et al. showed that unionization redressed the income inequality in America and Canada, especially in their public sectors. For American male workers, the reduction of wage inequality was 1.7 percent in the private sector, while the reduction was 16.2 percent in the public sector. For American female workers, the reductions were 0.6 percent and 10.7 percent in the private and public sectors, respectively. In Canada, reduction effects were likewise more noticeable in the public sector.<ref> {{cite journal 
| title = Unions and wage inequality: The roles of gender, skill and public sector employment.
| journal = Canadian Journal of Economics
| volume = 53 
| date = Feb 2020
| vauthors = Card D, Lemieux T, Riddell WC 
| pages = 140–173
| doi = 10.1111/caje.12432
| url = https://econpapers.repec.org/RePEc:iza:izadps:dp11964
}}
</ref>