Why Do Fewer Agricultural Workers Migrate Now?
研究了自1990年代末以来美国农业工人迁移率下降约60%的原因，发现三分之二的下降源于结构性变化，三分之一源于劳动力人口结构变化。
Abstract The share of agricultural workers who migrate within the United States has fallen by approximately 60% since the late 1990s. To explain this decline in the migration rate, we estimate annual migration‐choice models using data from the National Agricultural Workers Survey for 1989–2009. On average, over the last decade of the sample, one‐third of the fall in the migration rate was due to changes in the demographic composition of the workforce, while two‐thirds was due to changes in coefficients (“structural” change). In some years, demographic changes were responsible for half of the overall change.