When businesses are planning to invest, a key factor is the expected path of macroeconomic variables like inflation and real income growth.

FORBES: Federal Reserve Takes Another Step Toward Rule-Based Monetary Policy

Give me a real life problem and I could easily isolate variables.

FORBES: Can Video Games Make Your Kids Smarter?

Total employment is a real variable, and monetary actions can only impact nominal variables.

FORBES: When the Fed Makes Headlines, You Know We're In Trouble

At the same time, wages and salaries grew 0.4% in July, in line with headline inflation (up 0.4%) which translates, along with other variables, to a 0.1% decline in real disposable income.

FORBES: Consumption Picks Up In July Indicating Lower Risk Of Deflation

The real challenge is figuring out whether a particular storm or flood was due to climate change or natural variables, said Chris Field, founding director of the Carnegie Institution's Department of Global Ecology.

CNN: Extreme weather: Get ready to see more of it, scientists say