Economy Picking: What It Is and When It Beats Alternate Picking
Alternate picking requires strict down-up alternation with no exceptions (see [[alternate-picking-basics:the article on alternate picking]]). Economy picking is a deliberate break from exactly that rule, but only in one specific spot: at a string change.
How it differs from strict alternation
If a downstroke ends up right next to a thicker neighboring string, and the next note happens to be on it, economy picking keeps moving downward instead of switching to the upstroke alternate picking would call for. The pick simply continues the path it was already on, instead of reversing direction.
Why it can be faster
An extra pick reversal at a string change is added motion that produces no sound but still costs time (the same principle as in the article on downpicking, see the article on motion economy). Economy picking removes exactly that extra motion at string changes, leaving alternation within one string untouched.
It's not a full replacement for alternate picking
Economy picking isn't a substitute for alternate picking on every note, it's a targeted fix exactly where the pick's direction of travel and the string-change direction already line up. Within a single string, the alternation stays exactly as strict as usual.
The economy doesn't apply to every transition
If a string change needs motion in the direction opposite to where the pick is naturally heading at that moment, there's no economy to be had - ordinary alternate picking or string skipping applies instead (see the article on crossing strings). Economy picking is an opportunity for specific transitions, not a universal rule replacing the old one.
Drill: notice where the motion already lines up
Take a familiar pentatonic position (see the article on getting started improvising) and play it with alternate picking, noting the spots where the move to a neighboring string happens to line up with the direction of the next stroke. Those spots are the economy-picking candidates - leave the rest alone.
Try it in practice
Open the metronome