Hello friend,
The answer is:

Causes of non-cooperation movement:

The Non-Cooperation-Khilafat Movement was started by the Congress party in January 1921. 

Initially, this movement started with middle class participation in the cities.

Thousands of students, teachers and lawyers gave up their institutions and profession and joined the movement. 

This movement began in different cities across the country. The Non-Cooperation Movement dramatically AFFECTED the economy of British India.

The economic effects of Non-Cooperation Movement were as fallows
(i) As foreign goods and foreign clothes were boycotted, the import of foreign clothes halved between 1921 and 1922, and its value dropping from 102 crore to 57 crore rupees.
(ii) In many places, merchants and traders refused to trade in foreign goods or invest in foreign trade.
(iii) As people discarded imported clothes and started to use Indian clothes, production of Indian textile mills and handlooms went up. In this way, the Non-Cooperation Movement HELPED boost the Indian economy.

Rasons that this movement  was unfolded in following ways:

1.       Surrender of titles and honours and honorary posts.

2.       Boycott of LEGISLATIVE councils, boycott of law courts by the lawyers.

3.       Boycott of government schools and colleges and WITHDRAWAL of CHILDREN from these.

4.       Boycott of British goods.     

To get a popular support for the movement Mahatma Gandhi and Shaukat Ali toured extensively throughout India.

Hope this helps!!