This paper develops a product‐cycle model with costly technology transfer, which requires resources from both the North and the South. In the basic model, we show that strengthening intellectual property rights (IPR) protection induces a large technology transfer and narrows the North–South wage gap. However, we obtain an ambiguous result regarding the effect on economic growth, which depends crucially on the size of the transfer cost. Although strengthening IPR protection induces a high growth rate when the transfer cost is small, it can induce a low growth rate when the transfer cost is large. In the extended model, in order to examine what factors determine the transfer cost, we consider the situation where the Southern firms may misbehave and the Northern firms incur a cost to monitor them. We show that the degree of investor protection and the degree of morality in developing countries influence the size of the transfer cost, which affects economic growth.