This paper finds strong and robust evidence of convergence of labour produc
tivity in agriculture across all US states and 11 EU countries during 1970-
1992. Moreover, off-farm migration has a positive effect on the speed of co
nvergence, especially in the EU. Holding the off-farm migration rate consta
nt, the speed of convergence for EU countries (2.9 per cent per year) is st
ronger than for US states (1.9 per cent per year). A convergence speed of 2
.9 per cent means that an EU country needs about 10 years to eliminate one-
quarter of the gap between its initial output per worker and its own steady
state, and half a century to eliminate three-quarters of the gap.