TREE Universität Bern
TREE cohort 1: Development of (average) income from 2003 to 2014

TREE cohort 1: Development of (average) income from 2003 to 2014

What is TREE?

TREE (Transitions from Education to Employment) is a large national panel survey following up compulsory school leavers from all over Switzerland through their post-compulsory education and training and into employment and adulthood. Observation of the first TREE cohort (TREE1) started in 2000. To date, ten follow-up surveys have been conducted. In 2014, survey participants were, on average, 30 years old.

Description of the visualisation

By means of dumbbell plots, the visualisation displays the development of the various subgroups' average monthly gross income throughout the period of observation (2003-2014). The blue plots show the nominal income, the orange plots represent full time equivalents (FTE). Placing the cursor on any one of the blue or orange arrows will display the income development curve of the respective subgroup. Placing the cursor on any of the data points of the curve will a tooltip will provide you with its numeric value and the number of cases on which the value is based. If the number of cases is below 30, the numeric value is displayed in red in order to signal limited accuracy of the average's estimation. Please not that the calculation only accounts for individuals who were not in education parallel to their gainful activity.

Blue line = nominal income (Nm)

Orange line = full time equivalent income (Fte)

DE = German-speaking Switzerland

IT / FR = French- and Italian-speaking Switzerland

SEK1 = extended academic requirements

SEK2 = basic academic requirements

EDUP1 = no post-compulsory degree

EDUP2 = degree at upper secondary level

EDUP3 = degree at tertiary level

HED0 = no post-compulsory degree

HED1 = upper secondary level: vocational education & training (VET)

HED2 = upper secondary level: vocational baccalaureate

HED4 = upper secondary level: general education baccalaureate

HED30 = tertiary level: professional education and training (PET)

HED31 = tertiary level: university


You can download the original data HERE and the treated data HERE. THIS Github repository provided some inspiration for the present visualisation. Average income values are weighted, i.e. they account for (and correct) sample biases.


Programmer: Daniel Matyas

Bachelor Sport Science and Business Administration
Universität Bern


Data Coach:
Thomas Meyer

Co-head of the TREE study
University of Bern, Institute of Sociology

TREE Website