3.4.2. Symbiosis Coefficient

The symbiosis coefficient is usually used to measure the degree of mutual influence between symbiosis units. The symbiosis coefficient of the main quality parameters of tourism's carbon emission efficiency (TCEE) and the tourism economy's high-quality development (TEHQD) can be expressed as follows:

$$\Theta\_{\mathbb{C}}^{M} = \frac{|\delta\_{\mathbb{C}E}^{m}|}{|\delta\_{\mathbb{C}E}^{m}| + |\delta\_{\mathbb{C}E}^{m}|} \tag{8}$$

$$\Theta\_{\rm E}^{M} = \frac{|\delta\_{\rm EC}^{m}|}{|\delta\_{\rm CE}^{m}| + |\delta\_{\rm EC}^{m}|} \tag{9}$$

$$
\Theta\_{\mathbb{C}}^{M} + \Theta\_{\mathbb{E}}^{M} = 1 \tag{10}
$$

If θ*<sup>M</sup> <sup>C</sup>* = 0, it indicates that TCEE has no influence on the TEHQD. If <sup>θ</sup>*<sup>M</sup> <sup>C</sup>* = 1, it indicates that the TEHQD has no impact on the TCEE, but only the TCEE has an impact on the TEHQD. If 0 < θ*<sup>M</sup> <sup>C</sup>* < 0.5, it indicates that the TEHQD has a relatively large impact on TCEE. If θ*<sup>M</sup> <sup>C</sup>* = 0.5, the interaction between TCEE and TEHQD is the same. If 0.5 < <sup>θ</sup>*<sup>M</sup> <sup>C</sup>* < 1, it indicates that TCEE has a relatively large impact on the TEHQD.
