We construct a model of economic growth in which firms adopt more advanced technologies. In order to advance its technology, a firm must make an investment. The size of this investment depends on the size of the technology adoption barriers in the firm's country. Assuming a Markov chain for these barriers, we examine the amount of variation and persistence in the chain for which the model matches the observed output disparity across countries and the mobility of nations. Our calibration suggests a range for the size of these barriers of a factor five, and the presence of a barrier trap.