The problem isn't the average year over year. The problem is the outliers: we live in a modern world where massively game-changing events can occur and spawn whole new industries almost overnight without correspondingly wiping out old industries in the same time period (once such event -- the Internet -- is how you're talking to me right now). These events cause sudden huge upward swings in available goods and services, while gold remains stable. The only thing that can happen to a gold-standard economy in such a situation is crippling deflation.
I didn't see this for a week so you probably won't either, but here goes:
Productivity has grown a few percentage points a year, give or take, consistently, for a long, long time. One industry may boom for a decade, but the economy as a whole is relatively stable. I'm still not seeing anything wild.
