Sources: 1.
https://www.smithsonianmag.com/smart-news/american-bugs-almost-wiped-out-frances-wine-industry-180954619/
2.
https://io9.gizmodo.com/how-the-great-french-wine-blight-changed-grapes-forever-1691598233
- The root cause of the blight was Phylloxera aphid named small
insect like animal that attached itself to the best wines in France
and destroyed it completely.It is how the cause looked
like.
Impact on the Economy:
- Phylloxera, an insect that attacks the roots of grape vines,
destroyed 40 percent of French vineyards between
1863 and 1890, causing major income losses in wine-growing
departments Because the insects spread slowly from the southern
coast of France to the rest of the country, phylloxera affected
different regions in different years.
- Those born in affected regions were about 1.8 millimeters
shorter than others at age 20. This estimate implies that children
of wine-growing families born when the vines were affected in their
regions were 0.6 to 0.9 centimeters shorter than others by age 20.
This shows the grave consequences of it on human capital in
France.
- The loss in department agricultural income during the crisis
probably ranged between 16 and 22 percent in these regions, where
67 percent of the population was living in rural areas just before
the crisis (and 57 percent was living directly from agriculture
income).
- Rough estimates suggest that fall in department income in
wine-producing regions during these years may have ranged between
10-15% in the years of the crisis . During that time France was
also a Developing country and its Economy was predominantly
dependent on wine production. So such double digit shock affected
it badly.
Note: Concrete reliable facts on different estimates are not
available. The above facts has been collected from a research
paper.
Hope it serves the purpose.