Since the late 1990s, the share of agricultural workers who migrate within the United States fell by about 60%. On average over this period, one-third of the drop in the migration rate was due to changes in the demographic makeup of the workforce, while two-thirds was due to government and institutional changes in the market. However, in recent years, demographic change were responsible for nearly half of the overall change.
This reduction in the number of migrant farmworkers increases the risk that fruits and vegetables will not be harvested before they spoil. To avoid this problem, farmers will switch crops, automate planting and harvesting, or take other actions to reduce the need for seasonal agricultural workers. Only a major change in our immigration and guest worker policies is likely to increase migration within the country and postpone automation.