In the map of agricultural labor growth in Chinese region, the legend must include which is considered a high growth, medium and low growth of this variable.
As a suggestion for this paper or another, having the data of output, labor and land, it is also interesting to analyze the agricultural labor productivity explained by the agricultural land productivity and land-labor ratios. Maybe, some simple correlations between the growths of agricultural labor productivity vs land productivity and land-labor ratio could enrich this or future analysis.