Do the rich get richer in Basel?

Inequalities in income and wealth are a growing social issue ¹. This analysis seeks to quantify inequality in Basel, Switzerland, by analyzing the widening of wealth and income gaps between the city’s quarters.

Income and wealth

The data provided by Open Data Basel contains information on the wealth and income of the inhabitants of the 21 quarters of Basel based on tax-return documents. Figure 1 presents a schematic overview of the data.

flowchart LR
  A{Basel} --> B[Altstadt Grossbasel]
  A{Basel} --> C[...]
  A{Basel} --> D[Wettstein]
  B --> E[2001]
  B --> F[...]
  B --> G[2017]
  E --> H[Number of tax returns]
  E --> I[Mean income]
  E --> J[Mean Wealth]

Figure 1: Schematic overview of the data

Quantifying inequality

Figure 2 shows the development of income (panel A) and wealth (panel B) in Basel’s quarters in the years 2001 to 2017. It can be observed that the incomes in poorer quarters in 2001 declined with time, whereas those of richer quarters rose. Similarly, wealth in poorer quarters rose less strongly than wealth in quarters that started out wealthier. These results suggest a widening of income and wealth inequality in Basel.

Figure 2: Inequality in Basel. The figure shows the development of income and walth from 2001 to 2017, revealing a declining development for poorer quarters (darker shades) and an inclining development for richer quarters (lighter colors). The data was kindly provided by Open Data Basel-Stadt

Limitations and outlook

The presented analysis of income and wealth inequalities based on Basel’s quarters comes with several limitations. Most importantly, the analysis does not account for mobility, implying that some of the temporal differences could driven by changes in the quarters’ inhabitants. More detailed analyses which track inhabited across time will be needed to demonstrate conclusively a widening of inequality in Basel.

Appendix

Table 1 shows excerpt of the data for quarter Alstadt Grossbasel.

Table 1: Data excerpt for Altstadt Grossbasel

Quarter	Year	N	Mean income	Mean Wealth
Altstadt Grossbasel	2001	1673	87776	1014720
Altstadt Grossbasel	2002	1586	89525	1119065
Altstadt Grossbasel	2003	1568	83892	1029143
Altstadt Grossbasel	2004	1520	74973	515646
Altstadt Grossbasel	2005	1573	80261	657556
Altstadt Grossbasel	2006	1539	85263	1043716
Altstadt Grossbasel	2007	1571	90597	1032455
Altstadt Grossbasel	2008	1558	98148	799849
Altstadt Grossbasel	2009	1549	98185	1011185
Altstadt Grossbasel	2010	1596	94993	949972
Altstadt Grossbasel	2011	1603	93154	766231
Altstadt Grossbasel	2012	1644	95708	887314
Altstadt Grossbasel	2013	1628	101943	1011559
Altstadt Grossbasel	2014	1652	99494	1018173
Altstadt Grossbasel	2015	1675	98117	1015165
Altstadt Grossbasel	2016	1676	99020	1042452
Altstadt Grossbasel	2017	1694	97111	1060205

Footnotes

1. See https://www.un.org/en/un75/inequality-bridging-divide.