Fable
The accounting office reviewed only a few ledgers each night yet kept watch over the entire market
The market tax ledger was initially very small. The chief accountant went through all the stall ledgers every day, and could find even a single coin missing.
Later the stalls grew from a few dozen to several hundred, plus night markets, temporary sheds, and out-of-town goods. If they still wanted to review everything, the accountant could only skim hastily and would instead miss major errors.
The city magistrate first required every accountant to stay an extra hour. Everyone was exhausted, erroneous accounts did not decrease, and review turned into checking names off a roster. Someone proposed checking only the largest stalls. The large stalls became compliant, but small stalls and temporary sheds became the biggest source of tax evasion.
The young accountant changed his approach. He stratified by stall type, transaction amount, historical errors, and how recently the stall opened, and each night sampled a portion for close inspection; high-risk stalls were sampled more densely, while low-risk stalls still retained a random chance.
A few weeks later, the market found that spot checks were not laziness. The bookkeeper had the energy to examine the selected accounts in depth, and all stallholders knew they might be seen. Supervisory pressure did not disappear; it merely changed shape.
When a certain type of stall made repeated errors, more of them were sampled the following month; when rules were revised, the affected ledgers were specifically brought into the sample. The general ledger office finally learned to maintain genuine oversight with limited eyesight, rather than spreading eyes across the entire market.
Sampling is not always fixed either. When temporary sheds increased during the rainy season, the night market ledgers were sampled more densely; when returns were high after the festival, the related stalls also entered the focus. Random pressure applies to everyone; stratification gives more scrutiny to high-risk places.
The general ledger office also required that every spot check leave behind a reason and a result. If a layer stayed clean for a long time, the ratio could be lowered; if a layer made repeated errors, it was raised. The market learned to use a small portion of deep inspections to approximate the true state of the whole market. Later, when newcomers were onboarding, the veteran masters no longer started with abstract categories. Instead they had them review that failure: where intuition had been relied on, why the first patch was not enough, and how the new arrangement kept risk in a place that could be checked. Only when they could explain these details clearly, and point out when to keep using the approach and when to escalate, were they considered to truly understand the method. Later they also had newcomers rehearse the method: first let them do it the old way and see how errors appeared; then redo it under the new rules and see which step was blocked earlier and which step left evidence. Newcomers who could only recite the names would still misuse it in similar situations; only those who could state the applicable boundaries, the costs, and the remedies after failure were allowed to take on work independently.