think-stocks-and-flows-reasoninglisted
Install: claude install-skill product-on-purpose/thinking-framework-skills
<!-- thinking-framework-skills | https://github.com/product-on-purpose/thinking-framework-skills | Apache-2.0 -->
# Stocks and Flows Reasoning
People systematically misjudge accumulations. They confuse a stock (a quantity that builds up: cash, debt, a customer base, a backlog, technical debt) with the flows that change it, and infer the stock's direction from a flow's direction. The classic error: "the inflow is falling, so the stock is falling." It is not - the stock keeps rising while inflow exceeds outflow. This skill makes the structure explicit: name the stock, name its inflows and outflows separately, and reason about its trajectory from the net flow. The output is a **stock-flow map**. It corrects a specific, well-evidenced accumulation error; it does not claim to teach systems thinking wholesale.
## When to Use
- A quantity accumulates over time (runway, debt, backlog, headcount, customer base, reserves, technical debt) and the question is whether it is rising or falling.
- A trend in a flow is being used to infer the stock ("churn dropped, so the base is growing").
- Before acting on an "it's getting better/worse" intuition about an accumulation.
## When NOT to Use
- The quantity does not accumulate (a one-off event, a ratio with no stock).
- A simple direct relationship with no accumulation is all that is at play.
- Mapping forward consequences (use futures-wheel) or systemic causes (use iceberg-model); this is specifically about accumulation dynamics.
## Inst