PolicyEngine Macro
PE-MICROSIM
UK, US
microsimulation
- Horizon
- single policy year
- Runtime
- sub-second household; minutes population
- Access
- hosted, CLI, Python
US topic · scoring a policy change
What would a US reform do — and how far can the models follow it?
No series stands behind this one: pe-microsim scores a US reform over a single policy year, and neither US macro model accepts a PolicyEngine reform at all.
01 — where it stands
The numbers, as the snapshot stores them.
FRB-US
US
macroeconometric
- Horizon
- quarterly
- Runtime
- seconds to minutes
- Reform bridge
- none; cannot answer PolicyEngine reforms
US-HANK
US
heterogeneous-agent New Keynesian (sequence-space)
- Horizon
- quarterly impulse responses, typically 5 years
- Runtime
- ~18s cold per variant (steady state + jacobian, cached); instant warm
- Reform bridge
- none; cannot answer PolicyEngine reforms
This is the one topic with no official series behind it, so there is no vintage to date: what stands is a capability, and the cards above are read straight out of the committed capability registry rather than written by hand. pe-microsim is the only member covering both countries — the two US macro models are shock models, and the last row of each of their cards is the reason this page stops where it does.
02 — what the models see
The model view, and the same breath its limits.
pe-microsim is the scorer, and for the US it is the whole of it: it applies the reform to household microdata and reports taxes, benefits, net_income, revenue, distribution. It is production-ready for selected household applications, and its uncertainty is none for household arithmetic; survey/calibration uncertainty for population estimates.
The limit is the same structural one the UK page describes — a static costing has no macro feedback in it — but the US answer to it is different, and worse:
- pe-microsim cannot answer GDP, inflation, interest rates and macro feedback. A US costing from it is a static costing.
- On the UK side that gap is bridged: obr-macro supplies macro feedback through a reviewed reform translation, and psl-og+microsim adds olg-ge overlay on microsimulation. Both are uk-only.
- There is no US equivalent of either. Both US models record PolicyEngine reforms in their own cannot-answer field, and us-hank adds detailed tax reforms (only monetary/fiscal-spending/productivity instruments; the labor tax is endogenous). No mapping exists from a US statutory reform to a US macro model, and none is invented here.
One bridge does exist, and it runs the other way. The incidence commands take a macro shock, not a reform, and push its earnings consequences through the microsimulation — so the suite can answer “who bears this shock” for the US, and cannot answer “what would this reform do to output”.
Reform scoring is the one place where the macro models and the household model meet — see how a score is put together →
03 — run it yourself
Every number above is a command away.
One reform vocabulary, and for the US one scoring route. A $1,000 adult-dependent credit, scored statically on the population, then the macro-to-household bridge that does exist:
pe-macro parameters # curated reform parameter paths, live-resolved, both countries
pe-macro score --country us --reform '{"gov.irs.credits.ctc.amount.adult_dependent":1000}' --model microsim # static population costing
pe-macro population-impact --country us --reform '{"gov.irs.credits.ctc.amount.adult_dependent":1000}' --year 2027 # revenue and distribution for one policy year
pe-macro frbus-shock-incidence --var rffintay_aerr --shock 1.0 --year 2027 # a macro shock's earnings incidence — not a reformOver MCP: list_reform_parameters, score_reform, population_reform_impact for the population costing and household_reform_impact for a single household. recommend_model routes a question to a model, or refuses — and for a US reform needing macro feedback it refuses, which is the correct answer. Connect a client →
04 — the data behind it
Source, coverage, and the immutable file.
There is no vintage table on this page because no series in the store feeds a reform score. The provenance is different in kind: the microdata and parameter tree come from the policyengine-us country package, and the registry describes that vintage as “country package and dataset dependent; recorded per run”. Every run records its own, which is why two scores taken months apart can differ without either being wrong.
The store still matters here, one step removed: the six FRED series it holds are the outturns any macro leg of a US score would have to be judged against — and the absence of a US fiscal series in it is why this site has no US public-finances topic to carry the other half of a costing.
Dated, immutable JSON snapshots of every series this site reads — browse the store, its release calendar, and the as-of recipe →