# Urbanization and Grain Production Pattern of China: Dynamic Effect and Mediating Mechanism
## 5 Discussion
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Variables**} & \multicolumn{2}{c}{**Total Effect**} & \multicolumn{2}{c}{**Impact of Urbanization on M**} & \multicolumn{2}{c}{**Impact of Urbanization, M on the LQ**} \\ \cline{2-9}  & **InLQ** & **MCI** & **PS** & **ATECH** & **InLQ** & **InLQ** & **InLQ** \\ \cline{2-9}  & **Model 15** & **Model 16** & **Model 17** & **Model 18** & **Model 19** & **Model 20** & **Model 21** \\ \hline \multirow{2}{*}{LM} & \multirow{4}{*}{\(0.077\) ***} & \(0.945\) *** & \(0.841\) *** & \multirow{4}{*}{\(0.081\) ***} & \multirow{4}{*}{\(0.000\) **} & \multirow{4}{*}{\(0.000\) **} \\  & & (\(22.16\)) & (\(48.36\)) & (\(48.37\)) & & & \\ \cline{1-1} \cline{5-5}  & & \(0.500\) *** & \(0.276\) *** & \(0.172\) *** & & & \\ \cline{1-1} \cline{5-5}  & & (\(13.77\)) & (\(8.96\)) & (\(7.31\)) & & & \\ \cline{1-1} \cline{5-5}  & \(-0.0028\) *** & \(-0.219\) ** & \(-0.001\) *** & \(0.009\) *** & \(-0.0027\) *** & \(-0.0027\) ** & \(-0.0026\) ** \\ \cline{1-1} \cline{5-5}  & \((-2.78\)) & (\(-1.98\)) & (\(-5.71\)) & (\(7.41\)) & (\(-2.60\)) & (\(-2.30\)) & (\(-3.01\)) \\ \cline{1-1} \cline{5-5}  & \(\mathrm{YES}\) & \(\mathrm{YES}\) & \(\mathrm{YES}\) & \(\mathrm{YES}\) & \(\mathrm{YES}\) & \(\mathrm{YES}\) & \(\mathrm{YES}\) \\ \cline{1-1} \cline{5-5}  & \(0.00\) & \(0.03\) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) \\ \cline{1-1} \cline{5-5}  & \(0.34\) & \(0.92\) & \(0.46\) & \(0.16\) & \(0.34\) & \(0.22\) & \(0.52\) \\ \cline{1-1} \cline{5-5}  & Sargan P & \(1.00\) & \(1.00\) & \(0.00\) & \(1.00\) & \(1.00\) & \(1.00\) & \(1.00\) \\ \cline{1-1} \cline{5-5}  & Wald P & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) & \(0.00\) \\ \hline \hline \end{tabular} Note: ***\(p<0.01\), **\(p<0.05\), *\(p<0.1\). Round brackets show \(t\)-values. M is a collective term for mediating variables.  
\end{table} 
Table 8: _Cont._technology progress all play a partial mediating role and effectively offset the negative effect of urbanization on GPCI. That is, urbanization affects the GPP directly and indirectly through the allocation effect of cropland utilization, the structural effect of planting structure adjustment, and the innovation effect of agricultural technology progress. Here, the mediating effect of planting structure is more profound, followed by that of cropland utilization, and the mediating effect of agricultural technology progress is the least profound. Planting structure is a more important transmission path affecting GPCI, mainly because fluctuations in the planting area of different crops are the visual representation of the changing GPP. Due to changes in food consumption preference and production factor price during urbanization, farmers are more willing to plant cash crops with higher comparative returns. Labor mobility due to urbanization also prompts farmers to adjust their planting structure accordingly [55]. The increase in income and the easing of labor mobility constraints due to the off-farm transfer of rural labor increases the proportion of high value-added cash crops and investment in capital-intensive crops [56]. For cropland utilization, cropland area fluctuations due to urbanization change the number and intensity of replanting actions [57] and induce farmers to reallocate the intensity and structure of production factor inputs per unit area. Farmers balance inputs and returns and adjust their willingness and behavior regarding grain production, changing the level of cropland utilization and causing fluctuations in regional grain production. However, differences in average household cropland endowment and topographic characteristics between regions cause differences in factor input intensities, which in turn affect the GPP. Planting structure adjustment is also the result of farmers' balancing behaviors.