Laws of Succession and History
I'm a big fan of Jared Diamond's Guns, Germs, and Steel but my main criticism is that it only explains why Eurasians had more developed societies than others until about 1100. It does not explain why the first country to industrialize was not, say, Italy or China, but rather England. Moreover, it does not explain why Western Europe surged ahead of the Islamic world or East Asia over the past five hundred years and why Western Europeans at the dawn of World War I controlled or ruled over a majority of the Earth's surface.
I don't know the answer to these questions and don't know if there will ever be an answer that is completely convincing. However, there is one pattern in history that is usually overlooked. In Western Europe, monarchies had simple laws of succession (here is a Wikipedia entry explaining how monarchs are selected in different countries, most of them European) that mandated that the first-born son of the king take over when the king dies. By contrast, the Mongol Empire and kingdoms in the Islamic world had no such rules of succession. The result was that when the King or Emperor died, typically there was a bloody struggle for succession that sometimes degenerated into all-out civil war. Thus, the Mughal Empire disintegrated in 1707 upon the death of Aurangezeb after 181 years in existence and existed afterwards only as a shadow of its former self. In the case of the Mongols, the problem of not having a fixed rule of succession is clearest in 1241 as the Mongols advanced on Western Europe. When the Mongol commanders heard that Ogedei Khan (Ghenghis Khan's third son) died, they abandoned their advance and returned to the Mongol capital to elect a new Khan.
What is the point of all of this? If you don't have a clear rule of succession in place, there is more likely to be chaos when there is a transfer of power to a new person. From an economic standpoint, this should decrease a person's willingness to invest in the future because the future is so uncertain. And from a political perspective, the lack of a law of succession will increase in-fighting within the government as royal officials begin to form rival factions supporting different candidates for king or emporer. It will also, as happened to both the Mughals and Mongols, lead to a militarily weak and fractured state which will become vulnerable to foreign invasion.
This is not to say the transition to a new king was always smooth in Western Europe. However, I believe the transfer of power tended to be less chaotic and uncertain than in Central Asia or the Middle East and this may help explain the very different historical paths these regions have taken over the past 900 years.