Explanation

Leading indicators are economic variables that change before the overall economy changes, providing early signals about future economic activity. Coincident indicators change at approximately the same time as the overall economy, while lagging indicators change after the economy has already begun to follow a particular pattern.

Let's analyze each option:

A. Change in unit labor costs - This is typically considered a lagging indicator. Unit labor costs reflect the relationship between labor compensation and productivity, and these changes usually occur after economic conditions have already shifted.

B. Average weekly hours, manufacturing - This is a leading indicator. When businesses anticipate increased demand, they first increase existing employees' hours before hiring new workers. Changes in manufacturing hours often precede changes in overall economic activity.

C. Employees on non-agricultural payrolls - This is a coincident indicator. Employment levels typically change at about the same time as overall economic activity, reflecting current economic conditions rather than predicting future ones.

Therefore, among the given options, Average weekly hours, manufacturing (Option B) is the most likely leading indicator for an economy.