Benkard's (2000) L-1011 depreciation estimate implies far less organizational forgetting than the two prior studies his specification builds on

Benkard's estimate that ~61% of accumulated production experience survives a year on the Lockheed L-1011 program is, by his own account, a comparatively slow rate of forgetting. Benkard adopts the organizational-forgetting specification introduced by Argote, Beckman, and Epple (1990) — depreciation of experience by a constant factor δ each month — and directly compares his estimate to the two prior empirical applications of that specification: "Despite the fact that the estimate of the depreciation factor for this data is much higher and more precise than previous results obtained by Argote et al. (1990) and Darr et al. (1995), the implied depreciation rate still seems quite high." A footnote quantifies the earlier studies: "In the two previous examples in the literature, the depreciation parameter was estimated to be in the range 0.75-0.85, suggesting that only 5 to 15 percent of experience was retained from year to year."

Argote et al. (1990) studied ship production and Darr et al. (1995) studied a franchise business; both found organizations forgetting far faster than Benkard's aircraft-manufacturing case. This is a claim about what Benkard's own paper reports, not an independent read of Argote or Darr — the earlier studies' primaries are unread by this vault.