"only shortages of workers willing to work for less than what some employers are willing to pay."
Try only shortagees of workers willing to work for less than welfare pays!
No, as the "news" in the original thread points out; the wineries would have had enough workers if construction, even its lowest-skill tasks, and other trades did not offer higher salaries.
Slide those factors up the scale in all industries, especially those that more than others depend on domestic, as opposed to overseas, labor, and foreclose the ability to obtain cheaper illegal labor and you get greater investment in labor-saving technology, which results in job requirements for higher-skill levels of workers which supports higher salaries the business or industry was orginally competing with.
Continue an economy's addiction to cheap illegal labor and you get an economy that can grow with continued dependence on continued, cheap illegal labor; with a growing spread between an ever enlarging bottom and an ever greedier top - which the income data of the last six years reflect.
Its amazing how the Japanese economy pulled out of a ten-year, deflationary recession, avoided massive unemployment, continued to be a world export leader, did not see huge declines in wages and...........has very little immigration at all.
Yet, the economic mantra here attempts to portray "immigration" as almost Christlike in its salvatory attributes.