This paper empirically examines the determinants of migration inflows into 14 OECD countries between 1980 and 1995, focusing on the effects of average income and income dispersion in both origin and destination countries, as well as geographical, cultural, and demographic factors, and changes in destination countries' migration policies. The analysis confirms predictions of the international migration model but also reveals empirical puzzles. International migration patterns vary over time and across countries. Some OECD countries saw a decrease in annual immigrant inflows, while others experienced increases. The percentage change in annual immigrant inflows ranged from -42% in Japan to +48% in Canada. These changes were not monotonic across all destinations. Origin countries also showed significant variation. Several factors influence migration, but few empirical studies have explored what drives international migration due to past data limitations. Recent research highlights the economic benefits of free migration. This paper investigates the determinants of bilateral immigration flows, using a theoretical framework that considers both supply and demand factors. Data on immigrant inflows into 14 OECD countries is sourced from the OECD's Continuous Reporting System on Migration. The paper contributes to the literature by emphasizing the demand side of migration, particularly destination countries' policies, and by being the first to use OECD data to systematically analyze migration determinants. It also builds on previous studies on migration to the US and UK, and on labor movements in Canada, the US, and the US-Canada border.This paper empirically examines the determinants of migration inflows into 14 OECD countries between 1980 and 1995, focusing on the effects of average income and income dispersion in both origin and destination countries, as well as geographical, cultural, and demographic factors, and changes in destination countries' migration policies. The analysis confirms predictions of the international migration model but also reveals empirical puzzles. International migration patterns vary over time and across countries. Some OECD countries saw a decrease in annual immigrant inflows, while others experienced increases. The percentage change in annual immigrant inflows ranged from -42% in Japan to +48% in Canada. These changes were not monotonic across all destinations. Origin countries also showed significant variation. Several factors influence migration, but few empirical studies have explored what drives international migration due to past data limitations. Recent research highlights the economic benefits of free migration. This paper investigates the determinants of bilateral immigration flows, using a theoretical framework that considers both supply and demand factors. Data on immigrant inflows into 14 OECD countries is sourced from the OECD's Continuous Reporting System on Migration. The paper contributes to the literature by emphasizing the demand side of migration, particularly destination countries' policies, and by being the first to use OECD data to systematically analyze migration determinants. It also builds on previous studies on migration to the US and UK, and on labor movements in Canada, the US, and the US-Canada border.