By using OECD Input-Output in three different periods of time: mid-1990’s, beginning and end of the 2000’s, we discuss the evolution of their economic structures and their sectors along with a comparison among their structural similarities, measures by their Gross Domestic Product (GDP) per capita in purchaser’s power parities (ppp). Structural changes and similarities are discussed using fields of influence. The results revealed that economies tend to be stable in their structures depending on their level of development and the profusion of their fields of influence, with the exception of two countries with low GDP per capita but economic structures of developed countries.