But the main driver of today's volatility is the reality that investors are, to some extent, at the mercy of policymakers whose actions are neither predictable nor dependable.
The data show that outright discrimination isn't likely the main driver of today's overall gender pay gap.
Forecasters had expected the economy to tread water until the fiscal year ends next March; now some are lowering their forecasts because exports, the main driver of growth this year, have started to falter.
In the most violent region, southern Pará, where Zé Cláudio and Maria were killed, the main driver of blood today is the expansion of iron ore mining by Vale, the S11D project, and its infrastructure, such as the expansion of the Carajás railway.
We investigate learning models in a classroom environment which still remains the main driver of education today.
Higher spending by consumers and companies, which was the main driver of growth in 2005, is propelling Japan toward its longest postwar expansion.
Despite the government's plans to rebalance the economy away from over-reliance on consumers and towards more manufacturing and exports, spending has been the main driver of economic growth this year.
Eichengreen and Irwin have showed, convincingly, that the main driver of protectionism in the 1930s was the lack of perceived alternatives to boost employment.
Earnings reports are likely to be the main driver of equity market performance this week, with about 100 of the S&P 500 companies reporting second-quarter results.
Although the "smoking gun" of overt workplace bias was the main driver of gender pay inequity in the early 1960s, today the main causes are subtler.
