An autocratic style works when there is no need for input on the decision, where the decision would not change as a result of input, and where the motivation of people to carry out subsequent actions would not be affected whether they were or were not involved in the decision-making.
Democratic LeadershipIn the democratic style, the leader involves the people in the decision-making, although the process for the final decision may vary from the leader having the final say to them facilitating consensus in the group.
Democratic decision-making is usually appreciated by the people, especially if they have been used to autocratic decisions with which they disagreed. It can be problematic when there are a wide range of opinions and there is no clear way of reaching an equitable final decision.
Laissez-FaireThe laissez-faire style is to minimize the leader's involvement in decision-making, and hence allowing people to make their own decisions, although they may still be responsible for the outcome.
Laissez-faire works best when people are capable and motivated in making their own decisions, and where there is no requirement for a central coordination, for example in sharing resources across a range of different people and groups.
Discussion about Lewin's Leadership StylesIn Lewin et al's experiments, he discovered that the most effective style was Democratic. Excessive autocratic styles led to revolution, whilst under a Laissez-faire approach, people were not coherent in their work and did not put in the energy that they did when being actively led.
These experiments were actually done with groups of children, but were early in the modern era and were consequently highly influential.