Self-employed means being your own boss. It is having your own business.
Self-employment fractions are usually smaller in the advanced countries.
It is probable that the experience of Exchange rate crisis or Default crisis leads to increasing self-employment structures. It may be influenced by industrial composition, especially in countries whose economy is dependent of dominant tourism.
Meanwhile,
With new technologies being commercialized and decentralization among many aspects in the society growing, self-employment is progressing, expanding.
Steemit is pretty good example.