Method change May 2025. Before May 2025 the
figures come from the annual report (reference-date
based), from May 2025 on from the monthly
OgdAufrechteGewerbeberechtigung snapshots. The two
sources count slightly differently — hence the visible break
between April and May 2025. For the churn indicator we use only
the clean May-2025-plus window, so the calculation is not
distorted by the method jump.
Seasonal fluctuations. Smaller month-to-month
movements are normal — trade licences are issued in bursts
(month turns, quarter ends) and deregistered (often at year
ends). A single month at +5 or −3 is not a trend break.
What a line does not show. The stock is a
stock, not a flow. 500 active trade licences
at a steady monthly stock can mean: (a) 500 dormant businesses
with no movement, or (b) 480 stable plus 20 deregistering this
month and 20 newly registering. The churn indicator measures
exactly that difference — the curve does not show it.
Why we don't go back further. The GISA dataset
only exists in structured form from 2018, before that only as
non-anonymised internal data. Annual reports from 2019 could
theoretically be integrated — that is a planned expansion.
Currently: monthly snapshots since March 2025.