## 3 Materials and Methods
### Index Selection  
#### 3.2.1 Variable Determination  
(1) Explained variable--regional S&T innovation ability  
Nowadays, the measurement of regional S&T innovation ability can be divided into two categories. One of the common practices is applying a single index to measure the regional S&T innovation ability, such as the number of patent applications and authorizations [18], the gross value of high-tech industry [19], the sales revenue of new products [20; 21], etc. Another common practice is constructing the index system to measure the regional S&T innovation ability [22; 23; 24]. For example, [PERSON] and [PERSON] constructed a comprehensive index system of regional S&T innovation ability from three aspects, which are innovation investment, innovation performance and innovation environment [22]. Compared with a single index, the measurement results of a comprehensive index system can reflect the regional S&T innovation ability more scientifically and comprehensively. This paper applies the S&T innovation ability index in \"Report of Regional Innovation Ability in China\" issued by the China Science & Technology Development Strategy Research Group to measure the regional S&T innovation ability of each province. Based on the theory of regional innovation system, the \"Report of Regional Innovation Ability in China\" constructs an index system including knowledge acquisition, knowledge creation, enterprise innovation, innovation performance and innovation environment, so as to calculate the S&T innovation ability index of each province in China with comprehensiveness, authority and objectivity. (2) Explanatory variable--GPSTPS policy  
Economic activities and public governance activities must depend on policy guidance. Policy text is the core element of the policy. Based on GPSTPS, this paper makes the policy text analysis and policy content evaluation, attempting to construct a relationship model between GPSTPS policy and regional S&T innovation ability from the perspective of policy texts. With the aid of the PMC index model, this paper analyzes the rationality and feasibility of GPSTPS policy, obtaining the evaluation scores (PMC index) of GPSTPS policy of each province. Nowadays, most of the existing literature evaluates policies after the policy implementation, which belongs to a post-implementation evaluation method. However, this kind of method neglects the value of policy itself and cost is higher. The PMC index model aims at the policy itself and analyzes internal consistency, advantages and disadvantages of a policy from various dimensions. It is an advanced policy evaluation method in the world. Evaluating GPSTPS policy with PMC index model mainly includes the following two steps. (1) The first step is constructing a PMC evaluation index system of GPSTPS policy. To obtain the evaluation score (PMC index) of each policy, constructing a PMC evaluation index system is the first step. Based on the basic characteristics of S&T policy and the Omnia Mobilis hypothesis, a PMC evaluation index system of GPSTPS policy is constructed, which is shown in Table 1, including 10 primary variables and 43 secondary variables.