[6][7] Sayigh went to Sidon at age 13 for high school education and obtained a degree in business administration from American University of Beirut in 1938.

[8][9] During the Arab revolt in Palestine between 1936 and 1939 he began to take part in political activities boycotting the shops run by the Jews and wearing the fez as a symbol of nationalist resistance.

[10] Sayigh received his MA degree from the American University of Beirut in 1952, and his thesis was entitled Economic Implications of UNRWA Operations in Jordan, Syria, and Lebanon.

[11] During his university studies he joined the Syrian Social Nationalist Party (SSNP) led by Antoun Saadeh.

[8][12] Sayigh went to the US for the doctorate studies in 1954 when he was awarded a Fulbright scholarship and graduated from Johns Hopkins University in 1957 obtaining a PhD .

[2][13] His PhD thesis was entitled Entrepreneurship and development: Private, public and joint entreprise in underdeveloped countries.

[15][16] At the end of World War II Sayigh involved in the activities to raise funds to buy lands in Palestine to block the Jewish settlement.

[18] He also served as the treasurer of the PLO's National Fund from 1971 to 1974[15] and as its official representative to the World Bank.

[20] Sayigh was an advocate of the heterodox economics based on the public goods and social justice.

[3][10] Sayigh was the recipient of the prize of the Kuwait Institute for Scientific Research in 1981 and of the Abdullah Tariki Award in 2000.