4.1. Problem Description
The fundamental goal of an enterprise participating in PPP-FC is to maximize its profits, while the government is aiming to promote the interests of society; conflict is inevitable between the government’s “public-interest” goals and the enterprise’s “self-interest” goals. FC projects require large amounts of capital, have low yields and long payback periods, and lack sound laws and regulations, resulting in a lack of willingness and effort of enterprises to invest in FC projects [
14]. Therefore, the government provides a certain amount of subsidies to the enterprises to encourage them to invest in and operate FC projects. Then, the enterprise determines whether to invest in more construction and more efforts to consolidate farmland based on the level of government regulation and their own profitability. The government determines whether to provide incentives to the enterprise based on its performance and the government’s own regulatory expenses, causing a dynamic and repetitive game between the government and the enterprise. Evolutionary game theory refers to bounded rational individuals in a certain size group, under information asymmetry, repeatedly playing the game over time to achieve optimal strategy and maximized benefits, emphasizing a dynamic equilibrium. “Evolutionarily Stable Strategy” and the “Replicated Dynamic Equation” are core elements of the theory [
33,
34]. Evolutionary game theory is an important tool to solve such “cooperation and conflict” problems [
35], which has strong applicability in this paper. Therefore, this paper attempts to construct an evolutionary game model between the government and the enterprise to investigate the effect mechanism of the behavioral strategies of the enterprise under the government’s incentive and non-incentive strategies.
There are two strategic options for the government in PPP-FC projects, namely the incentive strategy and the non-incentive strategy for enterprises. (1) ‘Incentive’: In addition to the fixed project investment subsidies agreed upon in the contract, the government strictly regulates the behaviors of enterprises and comprehensively judges their efforts in FC projects based on their investment efforts and the effectiveness of the project so that they can be rewarded and punished accordingly. (2) ‘Non-incentive’: In addition to the fixed project investment subsidies agreed upon in the contract, the government believes that enterprises will work efficiently and consciously in pursuit of profits and therefore only slightly controls their deviating behaviors from the project objectives in monitoring the consolidation process, rather than adopting an incentive strategy toward enterprises.
As investors and implementers of FC projects, enterprises have two strategic options for high and low effort in the PPP project. (1) ‘High-effort’: This paper represents the level of effort of an enterprise based on its investment intensities and consolidation effects of PPP-FC. Therefore, adopting the “high-effort” strategy means the enterprise continues to work hard and invest more money in the implementation of PPP projects in addition to the paid cost (minimum investment criteria for project construction and operation) to obtain better results. (2) ‘Low-effort’: After paying the cost , the enterprise works passively and pays no further costs.
4.2. Model Assumptions
This paper employs the evolutionary game approach to dynamically analyze the behaviors of the government and the enterprise in PPP-FC. The main assumptions are as follows:
H1. The result of the game between the government and the enterprise directly determines the implementation effect of the project. The government is the manager and supervisor of the project and is the agent of other participating parties, safeguarding the fundamental socio-economic interests of the region, assuming that the government is a rational “social person” whose behavioral goal is to pursue the overall optimum of economic, social, and ecological benefits (as shown in Figure 1). As the main body of the market economy, the enterprise conforms to the assumption of a rational “economic person” and can weigh the pros and cons and behave for their interests. Both the government and the enterprise are bounded rational, and the information between the two subjects is asymmetric.
H2. In order to stimulate the enterprise to work hard to improve project performance, the government’s candidate set of strategies is incentive and non-incentive. The probabilities of government choosing ‘incentive’ and ‘non-incentive’ are and , respectively. The set of behavioral strategies for the enterprise is low-effort and high-effort. The probabilities of the enterprise choosing ‘high effort’ and ‘low-effort’ are and , respectively..
H3. When the enterprise chooses ‘low-effort’, the cost of building and operating is , and the return is . Otherwise, the enterprise chooses ‘high-effort’ and pays additional costs to obtain scale return from the modern agricultural production, where is the coefficient of the additional effort of the enterprise; hence, the total cost of the enterprise is .
H4. When the government chooses ‘non-incentive’, the government loosely regulates the process of FC, where the regulation cost is so small that it is assumed to be 0. In contrast, the government chooses strict regulation with regulation cost .
H5. When the government chooses ‘incentive’, the government rewards the enterprise for high-effort behavior with and penalizes low-effort behavior with . When the government chooses ‘non-incentive’, farmers, as beneficiaries, are also important forces for project supervision with a supervision level . Meanwhile, if the enterprise chooses ‘low-effort’, the “indolent behaviors” of the local government and the enterprise would be prosecuted for the superior government by farmers, resulting in fine to the enterprise and accountability of the local government from the superior government. We assume because decision subjects are more sensitive to losses than to gains [36].
H6. When the enterprise chooses ‘high-effort’, the returns of the government are and when it chooses ‘incentive’ and ‘non-incentive’, respectively. When the enterprise chooses ‘low-effort’, the returns of the government are and when it chooses ‘non-incentive’ and ‘incentive’, respectively.
Figure 2 shows the game process and its influence mechanism of the subjects in this study.
Table 1 shows the relevant parameters and their meanings for each subject.
Based on the above assumptions, the payoff matrix of the game between the government and the enterprise can be established as shown in
Table 2:
4.4. Equilibrium Point and Stability Analysis
To analyze the stable points of the system, let
= 0, and we obtain five equilibrium points: (0,0), (0,1), (1,0), (1,1), (
) (
), where (
) can be the equilibrium point only if
. Based on the analysis of Friedman [
37], the Jacobi matrix was established by deriving (4) and (8) of replication dynamic equations:
where
Then, the determinant (detJ) of the Jacobian matrix is:
The trace (
) of the Jacobi matrix is:
Based on the research of Friedman [
38], whether the above five equilibrium points are the evolutionary stability strategies (ESS) depends on
and
of the Jacobi matrix. When the corresponding matrix of the equilibrium point satisfies
and
, an evolutionarily stable strategy (ESS) exists. When the corresponding matrix of the equilibrium point satisfies
and
this point is unstable. When the corresponding matrix of the equilibrium point satisfies
or
it is a saddle point.
Substituting the coordinates of the five equilibrium points (0,0), (0,1), (1,0), (1,1), and (
) into the
and
of the Jacobi matrix, respectively, the values of
and
of each equilibrium point can be obtained as in
Table 3 below:
Based on the analysis of determinants and traces of the Jacobi matrix of the equilibrium points in
Table 3, five cases can be obtained, and the stability of each local equilibrium point is discussed as follows.
When
and
, the point (0,0) is the evolutionary stability point of the system, while (non-incentive, low-effort) is the evolutionarily stable strategy. In this case, the net profits of the enterprise choosing low-effort are more than choosing high-effort. As an economy pursuing profit maximization, the enterprise will inevitably choose low-effort behavioral strategies. At this time, if the government chooses the incentive strategy, the fines paid by the low-effort enterprise are far from making up for the high supervision costs. Even if the local government is held accountable by the superior government, it is reluctant to choose the incentive strategy. In this case, the government chooses the non-incentive strategy, and the enterprise chooses a low−effort strategy, resulting in an inefficient implementation of FC.
Table 4 shows the stability of each equilibrium point. When
, the equilibrium point
(1,0) is the only unstable point. When
, the equilibrium point
(1,1) is the only unstable point.
When
and
, the point (0,1) is the evolutionary stability point of the system, while (non-incentive, high-effort) is the evolutionarily stable strategy. In this case, the net profits of the enterprise choosing a high-effort strategy are more than choosing a low-effort strategy. Therefore, even without government incentives, the enterprise will implement a high-effort strategy spontaneously. On the one hand, because the enterprise initiatively chooses a high-effort strategy, there is no requisite for government to provide incentives. On the other hand, if the government provides incentives, it will not only pay supervision costs but also pay corresponding rewards to the high-effort enterprise. Therefore, the government prefers the non-incentive strategy. This case is the most ideal, which means even if there are no external incentives, the enterprise will maintain the positivism of high-effort work.
Table 5 shows the stability of each equilibrium point. When
, the equilibrium point
(1,0) is the only unstable point. When
, the equilibrium point
(0,0) is the only unstable point.
When
and
, the point (1,0) is the evolutionary stability point of the system, while (incentive, low-effort) is the evolutionarily stable strategy. In this case, compared with choosing a high-effort strategy, the profits of choosing a low-effort strategy for the enterprise are higher, so the enterprise would rather be punished than invest more in FC. Correspondingly, the government will impose penalties for the passive behaviors of the enterprise. In order to ensure the effect of FC, the government inevitably chooses the incentive strategy to encourage the enterprise to choose a high-effort behavioral strategy. However, even when the government adopts the incentive strategy, the enterprise still chooses a low-effort strategy, which belongs to the state of invalid government incentives and passive work of the enterprise, which is the most unfavorable stable state.
Table 6 shows the stability of each equilibrium point. When
, the equilibrium point
(1,1) is the only unstable point. When
, the equilibrium point
(0,1) is the only unstable point.
When
and
, the point (1,1) is the evolutionary stability point of the system, while (incentive, high-effort) is the evolutionarily stable strategy. In this case, when the enterprise chooses a high-effort strategy, the profits of the government adopting the incentive strategy are greater than the non-incentive strategy. At this time, under the strict supervision of the government, the enterprise is punished for adopting a low-effort strategy, causing the decline of their profits, and hence abandoning a low-effort strategy. Meanwhile, if the government chose the non-incentive strategy, the low-effort behavior of the enterprise and the behavior of the government’s loose supervision will be prosecuted by farmers in the project area, and the local government will be reprimanded by the superior government. Therefore, the government tends to choose the incentive strategy. The government’s choice of the incentive strategy and the enterprise’s choice of a high-effort strategy is a favorable stable state.
Table 7 shows the stability of each equilibrium point. When
, the equilibrium point
(0,1) is the only unstable point. When
, the equilibrium point
(0,0) is the only unstable point.
When
and
, the point (
) is the center point of the system. In this case, when the enterprise chooses a high-effort strategy, the benefit difference between the government’s choice of the incentive strategy and the non-incentive strategy is
. When the enterprise chooses a low-effort strategy, the benefit difference between the government’s choice of the incentive strategy and the non-incentive strategy is
. When the government chooses the non-incentive strategy, the benefit difference between the enterprise’s choice of high-effort and low-effort strategies is
When the government chooses the incentive strategy, the benefit difference between the enterprise’s choice of high-effort and low-effort strategies is
. At this time, there is a mixed strategy Nash equilibrium point (
) in the evolutionary game.
Table 8 shows the stability of each equilibrium point. The equilibrium points (0,0), (0,1), (1,0), and (1,1) are all saddle points, but (
) is neither the asymptotically stable point nor the evolutionary stability point. At this moment, the enterprise and the government will continuously adjust their strategies according to the opponent’s strategy, their behaviors will be periodic, and the evolution path will be an infinite loop of closed loops, as shown in
Figure 3.