In your opinion, which is more important for a country, political development or economic development?

You cannot do anything without money.

Politically-developed countries (my euphemism for democracies) make more money per head for their citizens than non-democracies, they also share it better (although increasingly badly since the 2008 crash).

(China makes loads of money, but the average Chinaman (or Chinawoman) is VERY poor compared with their equivalent in "the West".

So political development first, but economic automatically follows.

Economic -- although the type of political system will determine how the wealth is distributed.