Excludability of Biological and Physiological Channels

In Simple Words

Upgrading a car's fuel type or giving the driver a quick nap takes time to show results or wears off quickly during a long drive. But removing a heavy brick wedged under the gas pedal causes the car to accelerate immediately and maintain top speed all day long.

Research question

Immediate overnight productivity gains following liquidity infusions cannot be explained by biological pathways like caloric intake, blood sugar spikes, or sleep restoration.

Participants

N = 320 workers for breakfast recall (N = 408 workers across 17,441 worker-hours for hourly output tracking).

Study Design

Daily tracking of breakfast consumption (item, quantity, caloric type), hour-by-hour output persistence (testing 5–7 hours post-breakfast), and endline sleep quality scales.

Results

Cash infusion caused zero change in breakfast consumption (98% baseline rate) or sleep quality (p=0.671), and productivity gains persisted through the final 2 hours of the shift (+0.104 SDs, p=0.001), rejecting biological/nutritional mechanisms.

Takeaway

Focus workplace interventions on cognitive strain reduction rather than assuming worker underperformance stems primarily from caloric or sleep deficits.

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