Table 2. Heterogeneity in recruitment mixing behaviour over waves as observed during RDD survey in the Netherlands.

Mixing	Proportions waves 0–1 (n: 295)	correlation	Proportions waves 1–2 (n: 86)	correlation	Proportions waves 2 to 6 (n: 52)	correlation	Mean overall proportions (n: 433)	Overall correlations (n: 433)
Female–Female	0.61	0.02 [-0.09–0.14]	0.73	0.16 [-0.05–0.36]	0.83	0.23 [-0.05–0.47]	0.66	0.08 [-0.01–0.17]
Female—Male	0.39		0.27		0.17		0.33
Male–Male	0.41		0.43		0.50		0.42
Male–Female	0.59		0.57		0.50		0.58
Age 0–39 (a1)–Age 0–39 (a1)	0.56	0.23 [0.12–0.34]	0.57	0.52 [0.34–0.66]	0.86	0.65 [0.46–0.78]	0.60	0.33 [0.25–0.42]
Age 0–39 (a1)–Age 40–59 (a2)	0.12		0.29		0.14		0.18
Age 0–39 (a1)–Age 60+ (a3)	0.31		0.14		0.00		0.22
Age 40–59 (a2)–Age 0–39 (a1)	0.28		0.19		0.20		0.26
Age 40–59 (a2)–Age 40–59 (a2)	0.51		0.67		0.67		0.56
Age 40–59 (a2)–Age 60+ (a3)	0.21		0.14		0.13		0.19
Age 60+ (a3)–Age 0–39 (a1)	0.23		0.10		0.07		0.19
Age 60+ (a3)–Age 40–59 (a2)	0.29		0.21		0.20		0.26
Age 60+ (a3)–Age 60+ (a3)	0.49		0.69		0.73		0.55
Lower than academic education (A)—Lower than academic education (A)	0.65	0.29 [0.18–0.39]	0.67	0.41 [0.22–0.57]	0.68	0.21 [-0.06–0.46]	0.65	0.31 [0.22–0.39]
Lower than academic education (A)—Academic education (B)	0.35		0.33		0.31		0.35
Academic education (B)—Academic education (B)	0.65		0.76		0.53		0.66
Academic education (B)—Lower than academic education (A)	0.35		0.24		0.47		0.34