Everyday work, explained
How are person-hours estimated?
How does spending become an estimate of work time? Follow the calculation step by step, including the data it uses and its limits.
What does a person-hour mean?
One person-hour is a unit of work equal to one person working for one hour. Two people working for half an hour each also add up to one person-hour. This explains the unit; Behind Your Day does not know the actual participants or time their work.
The TWD 200 eating-out example in Taiwan gives about 0.43 person-hours. Converting to minutes gives a total of about 26 minutes of work. This adds up the work time attributed across the supply chain; it does not measure waiting time or reveal how many people participated.
Step 1: Convert spending to 2022 prices
The site adjusts for prices using the year of the purchase. It converts your amount to 2022 prices, then uses a 2022 reference exchange rate to express it in dollars, so data from different countries can be used in the same global model.
For the Taiwan example dated 15 June 2025, TWD 200 becomes about TWD 187.84 at 2022 prices. This puts the calculation on a common price basis. The consumer price index (CPI) measures overall consumer prices; eating-out prices need not have changed by the same amount.
Step 2: Estimate the production behind the purchase
Behind Your Day matches each purchase choice to product categories in official household spending statistics. For Taiwan, it uses DGBAS’s 2021 input-output tables to identify the products involved and the shares of domestic supply, imports, distribution costs and product taxes. Product taxes or differences that cannot reliably be allocated to production are not directly converted into work time.
The model then uses OECD’s 2022 inter-country input-output data to estimate the direct and upstream production associated with that demand. This brings the connections between industries into the calculation using statistical averages. It does not trace your payment, a shop’s invoices or a particular item’s origin.
Step 3: Convert production into working time
The model combines OECD employment counts for 2022 with ILOSTAT’s 2022 weekly hours actually worked in the main job. For each industry in each producing economy, it first estimates the average work time needed to produce a given monetary amount of goods or services. It then multiplies this by the production estimated in the previous step and adds the results.
Weekly hours are multiplied by 52 to estimate annual hours. Industries within the same producing economy use the same average working-hours data, so the result cannot reflect differences in actual working hours between industries or occupations. Results are organised into eight broad industry groups to make them easier to read.
What can this number tell us?
It can answer: “Based on average data, what work goes into supporting this kind of purchase?” It cannot answer how long this particular item took to make, how many people served you, or what workers were paid. A shop’s efficiency, recipe, brand premium and individual suppliers are not inputs.
We show “about 26 minutes” because this is an estimate, not a precise timing measurement. We also lack the statistical evidence needed to give a margin of error. These working hours cannot reveal wages either, because the model does not track individual workers’ income.