As usual, I try to simply supply some choice quotes but there's so much good stuff:
An "immature state" is a polity whose elites are dysfunctional, venal, and narcissistic; whose economy is not viable, frequently dependent on handouts; and whose coherence is threatened by a lack of social consensus. Immature states typically lack political traditions, change agents, goal-oriented bureaucracies, and institutional memory.
A "failed economy" fails to attract foreign direct investment. It is characterized by kleptocratic governments and rampant corruption, increased geopolitical risk, and lack of modern infrastructure. It features all-pervasive failure of institutions; lack of commitment to true reforms; absence of a functioning private sector; problematic mentality (laziness, passive-aggressiveness, pathological and destructive envy; xenophobia, resistance to learning, etc.); a low-level of research-and-development and innovation; an antiquated and dysfunctional education system; and primitive banking system and capital markets.
A "failed state" is a country whose government has no control and cannot exercise a monopoly on the legitimate use of force over a substantial part of its territory or citizenry. It is continuously and successfully challenged by private military power: terrorists, warlords, or militias.
A semi-failed state is a country whose government maintains all the trappings and appearances of power, legitimacy and control. ... Its institutions function...
Yet, the semi-failed state - while going through the motions - is dead on its feet. It is a political and societal zombie. It functions due mainly to inertia and lack of better or clear alternatives. Its population is disgruntled, hostile and suspicious. Other countries regard it with derision, fear and abhorrence. It is rotting from the inside and doomed to implode.