Table 5 Selectivity-adjusted earnings regressions (heckit) for self-employed and paid employees separately

Flexibility

(dummy)

0.172

(0.050)

0.023

(0.011)

0.189

(0.074)

0.038

(0.010)

Autonomy

Work outcome not prescribed in detail

(dummy)

0.051

(0.051)

− 0.001

(0.012)

− 0.176

(0.072)

− 0.012

(0.010)

Free how to perform work

(dummy)

− 0.125

(0.059)

0.019

(0.012)

− 0.178

(0.093)

0.022

(0.011)

Variety

Non-repetitive work

(dummy)

0.046

(0.053)

0.044

(0.012)

− 0.037

(0.071)

0.047

(0.010)

New tasks

(dummy)

0.050

(0.055)

0.020

(0.013)

− 0.072

(0.077)

0.010

(0.012)

Trying new things

(dummy)

− 0.033

(0.052)

− 0.006

(0.013)

− 0.082

(0.072)

0.024

(0.012)

Strained by risk

(dummy)

0.111

(0.079)

− 0.007

(0.020)

0.009

(0.141)

− 0.028

(0.022)

Pressure

(dummy)

0.206

(0.053)

0.016

(0.012)

− 0.056

(0.077)

0.025

(0.011)

Overstrain

(dummy)

− 0.086

(0.055)

0.002

(0.012)

0.160

(0.074)

0.016

(0.011)

Highest professional qualification (reference: none)

University (of applied sciences) degree

(dummy)

0.298

(0.102)

0.368

(0.028)

0.169

(0.161)

0.285

(0.023)

Master craftsmen/state certified technician/business administrator etc.

(dummy)

0.204

(0.117)

0.184

(0.029)

− 0.139

(0.190)

0.162

(0.028)

Vocational training

(dummy)

0.281

(0.121)

0.146

(0.025)

0.092

(0.146)

0.078

(0.019)

Working experience

(in years)

− 0.005

(0.009)

0.018

(0.002)

0.004

(0.011)

0.012

(0.002)

Working experience

(squared/100)

0.010

(0.016)

− 0.036

(0.004)

− 0.013

(0.022)

− 0.025

(0.003)

Working intermissions

(in years)

− 0.033

(0.020)

− 0.027

(0.005)

− 0.027

(0.022)

− 0.008

(0.003)

Working intermissions

(squared/100)

− 0.031

(0.001)

0.067

(0.036)

0.109

(0.137)

0.018

(0.015)

Tenure

(in years)

0.030

(0.008)

0.020

(0.002)

0.023

(0.012)

0.025

(0.001)

Tenure

(squared/100)

− 0.068

(0.020)

− 0.027

(0.004)

− 0.020

(0.039)

− 0.033

(0.004)

Skills required at work

(16 dummies)

Yes

Yes

Yes

Yes

Tasks occurring at work

(17 dummies)

Yes

Yes

Yes

Yes

Physical working environment

(11 dummies)

Yes

Yes

Yes

Yes

Migration background

(dummy)

0.170

(0.079)

0.001

(0.019)

0.019

(0.110)

− 0.027

(0.017)

Family status

(5 dummies)

Yes

Yes

Yes

Yes

Place of residence

(16 “Bundesländer” dummies)

Yes

Yes

Yes

Yes

Constant

2.325

(0.408)

2.018

(0.043)

2.571

(0.477)

1.926

(0.036)

Inverse Mill’s ratio

− 0.065

(0.136)

0.109

(0.051)

− 0.304

(0.172)

0.109

(0.062)

No. of observations

800

5552

499

6436