All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.
The basic principle is that learning English, economics, or public administration is permissible; Allaah, The Exalted, says (what means): {It is He Who created for you all of that which is on the earth...} [Quran 2:29] The verse was revealed in the context of reminding the people of the great blessings that Allaah conferred upon His slaves, indicating that the basic principle is that all things are lawful unless proven otherwise by sharee'ah evidence.
The fact that the curricula of these subjects contain un-Islamic topics does not entail deeming it unlawful for the Muslim to learn them as long as his intention is not to implement them and act upon them and it is not feared that it would be a source of fitnah (temptation, tribulation) for him. He should have adequate, sound knowledge to repel and refute misconceptions as well as the firm conviction to guard himself from sinful desires.
At any rate, the Muslim should have a good intention in acquiring knowledge and learning; he should intend to serve his religion and the Muslim nation so as to attain success and happiness in the worldly life and the Hereafter. It has been narrated on the authority of ʻUmar ibn Al-Khattaab that the Prophet said, "The (reward of) deeds depend upon the intentions, and every person will get the reward according to what he has intended..." [Al-Bukhari and Muslim]
Allaah knows best.