I also see within this a combination of two theories, one borrowed from economics and the other from evolution.
From an economics view of demand and supply- surplus causes chaos. From an organisational standpoint- a surplus of eligible talent will lead to lower investment in capability development as a company will go to the market and back fill with ease. This erodes an organisations learning capacity.
Given that right talent is scarce, a learning environment is crucial for an organisations health. Linked to this is Raven’s theory – if you look at an organisation as an organism, the rate of learning must atleast be equal to or greater than the rate of change in the external environment. This leads to evolution.
Considering successful organisations have to evolve – they have to creat a learning culture. Then they win. And people want to be part of a winning, learning, evolving team.