**1. Introduction**

As the key elements of agricultural production, the movement and reorganization of labor and land are not only significance to address problems affecting farmers, rural areas, and agriculture in China, but also beneficial for consolidate progress toward poverty alleviation and achieve common prosperity. However, in light of fundamental national conditions in China, which include a large population and limited land, as well as the institutional arrangement of a household contract responsibility system with output-linked compensation, the problems of the small scale of agricultural operations, the relatively low agricultural labor productivity, and the continuous increase of agricultural surplus labor become extremely prominent. In order to solve the above problems, farmers select different forms of farmland transfer (FT) and labor migration (LM) to optimize the allocation of land and labor factors from production sectors with relatively low marginal productivity to production sectors with relatively higher marginal productivity, so as to continuously improve the income of farmers and achieve the goal of rational allocation of land resources and

**Citation:** Wang, Y.; Liu, G.; Zhang, B.; Liu, Z.; Liu, X. Coordinated Development of Farmland Transfer and Labor Migration in China: Spatio-Temporal Evolution and Driving Factors. *Land* **2022**, *11*, 2327. https://doi.org/10.3390/ land11122327

Academic Editor: Tao Liu

Received: 24 November 2022 Accepted: 16 December 2022 Published: 19 December 2022

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labor resources [1–3]. In fact, influenced by resource endowment [4,5], welfare guarantee function of rural land [6], farmers' risk awareness [7], land transfer cost [8], family labor allocation [9], the high level of labor migration, and a high level of farmland transfer has not occurred concurrently, and the farmland transfer has a deviation from labor migration in the development process. Such incoordination directly affects the orderly economic and social development, as well as agricultural and rural modernization construction. The issue of coupling and coordinated development of FT and LM has become one of the key concerns of rural economic research in the context of rural revitalization strategy. Therefore, this study intended to focus on the above questions and provide a reference for decision making to advance the mutual promotion of FT and LM in China and establish a positive interaction with organic coupling and coordination between them.

At present, the academic community has accumulated abundant research results related to FT and LM; there are two general categories of existing literature. On the one hand, it explored the mutual influence of FT and LM. The majority of the literature held the view that FT and LM had an inverted "U" relationship [10–12]. Concerning the effect that the FT has on LM, the current fragmentation of land prevents the rural labor migration and is not good for agricultural mechanization [13], while farmland transfer and land consolidation may solve this problem by reducing agricultural labor intensity, realizing labor resource reallocation, improving the use efficiency of rural labor force [14–16], improving the level of labor migration [17], increasing the income of farmers [18,19], and reducing the urban– rural disparity [20]. The decision-making behavior of farm households to transfer in or out farmland is correlated to the number of non-agricultural labor forces and agricultural labor productivity [21], whereas changes in land use are brought about by large-scale land transactions, while large-scale land transactions lead to changes in land use, both of which have a direct effect on household labor distribution and gender division of labor [22]. In addition, the absence of farmland transfer right [23], household income increases after labor migration [24], a well-functioning land market [25], and the instability of the duration of farmland contractual rights [26] can also significantly affect the level of LM. Due to the fixed time and maturity of crops, labor demand is mainly distributed throughout the growing season [27]; this means that the rural labor force has the possibility of moving out for employment. In terms of the impact of LM on FT, current studies concluded that LM could influence FT [28–31], specifically, the level of non-agricultural income and the proportion of non-agricultural employment positively affect the farmland transfer [32]: the larger the household labor force, the greatest probability that the peasant household is to transfer to the farmland, and the larger the proportion of non-agricultural labor force in the household labor force, the greater the possibility to transfer out of the farmland [33]; most current literature emphasizes that LM was beneficial to promoting land reallocation and reuse [34] with a phased impact [35]. Meanwhile, the expansion of urban non-agricultural population size has also become the main driving force of FT as the rural labor forces move to cities and towns [36,37].

On the other hand, the relationship between LM and the FT has been the subject of discussion. Existing studies have found an interaction relationship between LM and the FT; with the continuous rise of non-agricultural wages and a large number of rural labor force transferred to cities, the phenomenon of farmland abandonment is increasingly serious [38–41]; to solve this problem and improve the allocation efficiency of land resources, farmland should be transferred from farmers not willing to manage agriculture or with relatively lower agricultural productivity to those willing to manage agriculture or with higher agricultural productivity [42]. However, for some parts of the transferred labor force, the social pension function of farmland increases the opportunity cost of labor force transfer, thus hindering the transfer of farmland [43]. Some studies suggest that the development of LM and the FT are affected by the same factors, such as farmland certification [44–47]. In addition, a few existing studies have revealed the coupling and coordinated relation between FT and LM from the theoretical and practical levels. In the coupling theory analysis study, research scholars studied the internal mechanism of FT and LM based on different

theoretical perspectives. For example, Wang et al. measured the CCD of FT and LM in Xinjiang, the study found that the CCD of FT and LM in Xinjiang was at the stage of high coupling and primary coordination, and there were large differences between regions [48].

To sum up, the existing literature is not comprehensive in the explanation of the relation between farmland and labor force. In reality, most existing studies have focused on the interaction between FT and LM and lack research on the spatial distribution characteristics and driving factors of the coupling coordination degree (CCD) between the farmland transfer and labor migration. The research units placed emphasis on a province in China, lacking meso-scale provincial comparative analysis. Therefore, it is necessary to conduct detailed and in-depth research on the CCD of FT and LM in China to obtain reliable conclusions, and the research conclusions of this study offer an effective supplement to the current research on resource allocation and the agricultural economy.

The questions that this paper hopes to answer are as follows: What is the coupling coordination degree between the two systems of FT and LM in provinces of China? What are the changes of the coupling and coordination relations between them in different space and time? What are the driving factors affecting the changes in the level of coupling and coordination between them? This study had three main research objectives: (1) Using the data of the panel statistics from 2015 to 2019, applying the linear weighting method to measured farmland transfer and labor migration evaluation index and comprehensive evaluation index in China, and constructing a coupling coordination degree model (CCDM) to measure the CCD of FT and LM in 30 provinces/autonomous regions/municipalities (hereafter referred to as provinces) in China. (2) Applying the exploratory spatial data analysis method (ESDA) investigate the spatial differences in the CCD. (3) Using gray relational analysis model (GARM) to determine the driving factors behind CCD of FT and LM.

This study contribution of this paper is as follows: Reliable evidence regarding the coordinated development of farmland transfer and labor migration was obtained by constructing CCDM. This study also adds evidence to the research framework on the coordinated development of farmland transfer and labor migration and provides guidance to implement the rural revitalization strategy for other regions and provinces.

The rest part of this paper is structured as follows: The second part introduces the data sources, study area and research methods, and the third part presents the econometric analysis results of the coupling coordination, spatio-temporal evolution, and driving factors of FT and LM. The fourth part analyzes and discusses the empirical results, and the fifth part draws the conclusions of this paper.

## **2. Materials and Methods**

### *2.1. Data Sources*

The data of FT and LM used in this paper came from China Rural Management Statistical Annual Report. The social and economic statistics data were taken from the China Statistical Yearbook and the China Rural Statistical Yearbook. The relative indexes are calculated according to the corresponding original data, and the individual data with missing or abnormal data are corrected by the mean replacement method. Moreover, due to the lack of some statistical data in Hong Kong, Macao, Taiwan, and Tibet, this study identified 30 provinces in China as the research units.
