Flow State
The flow state economics equation: 4 hours uninterrupted = 20 hours of interrupted work.
Flow state is a state of deep, focused concentration where productivity can reach 5× normal levels (McKinsey study). Entering flow requires 15-23 minutes of uninterrupted focus as the brain loads complex mental models. Breaking flow is immediate - a single interruption clears working memory and requires another 15-23 minutes to rebuild. This creates an asymmetric cost: a single 30-minute meeting can destroy 3.5 hours of maker time (9-11 AM unable to enter deep work due to meeting looming, 11-11:30 meeting itself, 11:30-12:30 recovery time).
Business Application of Flow State
The flow state economics equation: 4 hours uninterrupted = 20 hours of interrupted work. Companies protecting flow through 'No Meeting' days (Shopify, Slack, Asana) see 33-40% productivity gains. The maker vs. manager schedule distinction recognizes that different work requires different time structures.