There are large international differences in how wages evolve over careers between the US and Europe: between the ages of 21 and 50, average real wages rise by 80% in the US, while in Germany, for example, they only increase by half as much. At the same time, inequality rises much more sharply in the US over careers. It is important for both public policy and economic research to understand the forces behind such large transatlantic differences in how wages develop over the life course. In my project "Labor market frictions, wage growth and lifetime inequality", I investigate whether large international differences in labor market mobility can explain the significant differences in wage growth and lifetime inequality between the US and Europe. I document marked differences in labor mobility as well as wage growth, and find that the average American changes jobs more than twice as often as the average European. Previous research has shown the importance of such job-to-job switches for wage growth - on average, wages rise by 10 percent in the context of a job switch. I develop a model that captures the importance of labor mobility, showing important interaction effects between mobility and human capital investment decisions. Finally, I analyze the institutional differences that underlie the large international differences in labor mobility.