Scientific and technical knowledge is mostly concentrated in specific areas, but it does flow between different regions. Researchers studied how knowledge moves between innovative hubs and its impact on regional innovation. They found that knowledge flows in a top-down, hierarchical way within research networks. After the EU enlargement, knowledge started flowing more from west to east in some networks and from east to west in others. This means that the EU is now more of a knowledge exchange platform for some countries, while for others, it's mainly a one-way channel for knowledge transfer.