Political instability may impact a country’s development either positively or negatively. With political uncertainty, economic development may be slowed. Investors may be hesitant to invest in a country with political instability. The investors may fear that they will not benefit from their investment. Political instability creates uncertainty that tends to turn away people from being willing to invest in a country. Political uncertainty may also make it difficult for the people in a country to get decent jobs, which could hurt spending and saving. Political instability may make it difficult for critical institutions to function. For example, political instability may hurt the development of a good educational system. The necessary funds needed to provide a strong educational system might not be available.

However, political instability could lead to a change in a government that might turn around an unstable situation. If a new government comes to power and provides more certainty and stability, then a country may benefit from the instability of the previous government. If the new government provides stability, then economic growth may occur with more investment.

Sometimes, political stability leads to less change and development, especially if the government isn’t elected. In these instances, there is little incentive to change. Corruption could also develop. The country’s development could be harmed.

Generally, political stability is desired to help a country’s development. However, it isn’t always necessary and, depending on circumstances, political stability could slow development within a country.

Yes, experts believe that political instability affects a nation's development (see the article from the World Bank in the links below). An unstable government is one that is prone to collapse because it is plagued by internal disagreements, by competition from other political parties, or by disillusionment among the people in a nation.

Political stability is necessary for economic growth for many reasons. An unstable government reduces investment because people are unwilling to invest in a government that seems likely to topple or be toppled. In addition, political instability stymies economic growth because people cannot afford (either economically or mentally) to support innovation when they are worried about political stability. In addition, many people feel tempted to emigrate from the country if it is plagued by instability. Finally, a stable government is necessary to carry out large-scale investment and infrastructure projects, as these projects take time and political and financial capital to complete. 

An unstable government can hinder a country’s development in a number of ways.  Some examples include:

• Inability to provide medical and educational infrastructure.  Part of development involves increasing things like life expectancy, overall health, and literacy among the population.  A stable government is more likely to be able to provide the infrastructure needed to improve its population’s standing in these measures.  Building good schools and good public health systems is not something that can be done piecemeal.  Instead, it needs sustained effort of the sort that can best be provided by a stable government.
• Inability to provide a good climate for business.  Economic development is an important part of development.  Businesses are not likely to invest in a country if its government is unstable.  They will fear, for example, that the government will fall, causing chaos.  They might also fear rash actions on the part of the government (such as expropriation) that will destroy the value of their investments.  If businesses do not feel safe, they will not help to create economic development.

In these ways and others, a stable government is important for development in a country.