Defense contractors retain engineers for two reasons. First, engineers
work on current-period production contracts. Second, engineers conduc
t independent research and development (IR&D) and write bids and propo
sals (B&P) for future contracts. The amount of IR&D/B&P activity, howe
ver, understates the amount of effort devoted to learning that reduces
the cost of future production. Even some engineers who work on curren
t-period production may engage in learning, as a by-product of their e
fforts. This article develops and implements a model for estimating th
e volume of learning activity undertaken by four large manufacturers o
f military aircraft. (C) 1994 John Wiley & Sons, Inc.