*4.2. Risk Coupling Value Calculation*

(1) Single factor coupling probability

By analyzing the statistical data of social stability risk accidents of major projects, the probability that government factors do not affect the social stability risk of major projects is as follows: *P*<sup>0</sup> ... . = *P*01,000 + *P*00,100 + *P*00,010 + *P*0,0001 + *P*01,100 + *P*01,010 + *P*01,001 + *P*00,110 + *P*00,101 + *P*00,011 + *P*01,110 + *P*01,011 + *P*00,111 + *P*0,1111 = 0.786. Similarly, *P*<sup>1</sup> ... ., *P*.0 ... , *P*.1 ... , *P*..0.., *P*..1.., *P* ... 0., *P* ... 1., *P* . . . .0, *P* . . . .1 can be calculated, and the calculated results were tabulated in Table 7.

**Table 7.** Single factor coupling probability.


(2) Tow-factor coupling probability

By analyzing the statistical data of social stability risk accidents of major projects, the probability of accidents when government and public factors do not participate in risk coupling is *P*<sup>00</sup> ... = *P*00,000 + *P*00,100 + *P*00,010 + *P*00,001 + *P*00,110 + *P*00,101 + *P*0,0011 + *P*00,111 = 0.314. Similarly, *P*01..., *P*10 . . . , *P*<sup>11</sup> ... can be calculated, and the calculated results were shown in Table 8.


(3) Multi-factor coupling probability

By analyzing the statistical data of social stability risk accidents of major projects, the probability of accidents when the government, the public, and economic factors do not participate in the risk coupling is *P*000.. = *P*00,000 + *P*00,001 + *P*0,0010 + *P*00,011 = 0.268. Similarly, *P*100.., *P*010.., *P*001.. can be calculated, in which Tables 9 and 10 present the results.


**Table 9.** Three-factor coupling probability.

**Table 10.** Four-factor coupling probability.

