The plague, also the black death caused a drastic fall in the total population of the inhabitants of Europe.
Explanation:
The competition and congestion that was being experienced eased. Labour became a scarse resource out of the sudden reduction, there were plenty of jobs, with good pay, compared to the previous competition out of the large population of peasants.
There was a lot of land and therefore no congestion, land became cheaper and consequently led to high mobility.
