Definition: Correlation coefficient
OECD - Business tendency surveys
Given a pair of related variables (X and Y), the correlation coefficient (r)measures the degree to which they co-vary in a linear fashion. r will be positive when the two variables move in the same direction and negative when the two variables move in opposite directions. r takes values from -1 to +1. Ignoring the sign, the larger the value of r the greater the strength of the association between the two variables.
Organization for Economic Cooperation and Development (OECD), "Business Tendency Surveys - A Handbook", OECD, Paris, 2003