This chapter begins with an introduction describing the book’s background as deriving from three previous works on how emerging nation business groups significantly contribute to economic development, emphasizing case studies of Thailand and other Asian countries. Four purposes of the book are specified: assessing if a latecomer country is trapped in middle-income nation status, reviewing Thailand’s industrial and economic growth strategies; showing that business groups are essential for economic advancement and avoiding the middle-income trap; and indicating the route to the subsequent developed nation status. The 11 chapters are divided into three sections: (1) theories and issues; (2) policies, target industries, and foreign investors; and (3) company case studies in Thailand and policy recommendations. Significant terms are defined. Finally, target readership and preliminary reading accords are discussed.International research publications explore the middle-income trap from macroeconomic and state development policy viewpoints. Simultaneously, several academic works study latecomer nation business groups from a microeconomic and firm competitiveness viewpoint. The present study is the first empirical book to analyse the role of business groups in relation to the middle-income trap.