The more complicated government becomes, the less flexible and creative it is in relation to the demand placed upon it by changing needs. As societies grow in size and complexity, central governments themselves grow more complex in the attempt to deal with the ambiguities in these societies.
Stable societies, like the USA and the UK, which are spared the trauma of military defeat or social upheaval, almost inevitably tend to become barnacled with interest groups whose goals are to claim a larger share of the pie for themselves and their members. As they assert their claims, they impede the society's ability to make needed policy changes and economic shifts, so that growth slows and government becomes ever less responsive. By contrast, countries like Germany and Japan, which have had turbulent histories, are less encumbered by interest groups, and therefore see their economies grow faster, their politics adapt more swiftly to change. Because the interest-group network will not allow failed or outdated policies and programmes to die, there is neither the money nor the will to try new approaches.