Mr Biden is a clear outlier in terms of the number of undocumented, or illegal, migrants crossing the border. During his presidency there have been record numbers of apprehensions and expulsions at the border; nearly 250,000 people crossed in November alone. The Pew Research Centre reckons that there were 10.5m illegal immigrants in 2021, the latest year available. That is roughly the same as in 2017 and fewer than in any other year between 2005 and 2015. It also puts illegal migrants at roughly 3% of people living in America and 22% of the country’s foreign-born population—the lowest shares since the 1990s. This data does not include estimates since the latest wave of encounters at the border; some 600,000 people are thought to have slipped through undetected in 2023.
- Date Posted:
- January 25, 2024
We focus the bulk of our explanation on a theory: that demand increases endogenously due to spillovers in demand for opioids across people. [Here] spillovers are dynamics such as the spread of information about the substances, and ease and safety in ability to acquire the substances. We test for spillovers using county-level data on opioid deaths from 1991–2018 and opioid shipments from 2006–2009, combined with data on friendships and distance between counties. Estimating a model with addiction and spatial spillovers, we find large spillovers in opioid use and deaths across areas. A shock that increases opioid death rates by 1 in an index county causes 0.38 to 0.76 more deaths in other counties because of spillovers. Because opioids are addictive, this leads to even more deaths and spillovers in future years. In some specifications, these effects are large enough to generate a continuously increasing epidemic without any ongoing changes in demand or supply. We estimate spillovers explain 84 to 92% of opioid deaths from 1990 to 2018 and are the main reason deaths have increased for so long. In our preferred models, spillovers explain most opioid deaths since 1990 and are the main reason the epidemic has not burned out.