Immigration Reform and Control Act was passed that granting people amnesty would induce
most of them to leave agriculture were incorrect,” (p. 427) and “.....the steady state probability of
working in agriculture is higher for someone with amnesty than for an undocumented worker, so
that IRCA increased the long-run probability that people granted amnesty stayed in agriculture.”
(p. 437)
However, this conclusion is a little problematic. As the authors mentioned in their work,
the portion of undocumented workers in the agricultural labor force grew substantially in the
1990s. In the sample (1987-91) used by Tran and Perloff, only 7% are undocumented workers.
According to the NAWS data, the portion of undocumented workers rose to 46% for the years
1995-98, and 48% for the years 2002-2004. This implies that there has been a large-scale inflow
of undocumented workers into the agricultural labor market and a large-scale outflow of
documented workers from it. The latter might mean that documented workers tend to leave
agriculture in the long-run: the opposite observation to their conclusion.
There are some concerns that might lead to statistical problems in their work. First, a data
sample (1987-91) is taken in a transitional period in the sense that workers granted amnesty might
not have had enough time to move to other industries. It is also a transitional period in another
sense that the legal status of many workers changed. The study is unable to control for this status
change using the observed status at the time of interview, the only legal status information
available in the NAWS data. As a result of the 1987-91 sample used, the study cannot capture the
major inflow of undocumented workers from foreign countries after IRCA and who have become
a major component of the labor force in agriculture. The most serious problem, however, is that
the study tries to estimate a probability matrix and a steady state for the whole migration process
using data from only a small sector (the agricultural labor market). Most migration for any status