Hacktoberfest 2026: as issues que os mantenedores marcaram para outubro, abertas e boas para iniciantes. Ver issues do Hacktoberfest

F1: fertility-rate predictor inconcistency between estimation and Java implementation

Aberta
  • Algo errado?
#538 0 comentários 0 reações 1 responsável Ver no GitHub

@dariaple já está trabalhando nisso.

Desde 23/10/2026.

Avaliação

Esta issue ainda não foi avaliada.

Descrição

The UK F1 equation is estimated using a national annual fertility-rate series, but Java evaluates the coefficient using a regional measure derived from population projections. This mismatch remains in develop at commit 971d050, checked on 23 October 2026.

Estimation

The UID construction assigns dukfr by calendar year only, with the label "UK General fertility rate (ONS)": 02_create_UKHLS_variables.do, lines 1846–1867.

The regression preparation then sets fertilityRate = dukfr (variable_update.do, lines 679–680), and the active F1 probit includes fertilityRate. Thus all observations in the same year receive the same national rate, irrespective of region.

Java implementation

For ordinary simulated persons, the FertilityRate getter instead calls getFertilityRateByRegionYear(getRegion(), getYear()). The lower-case fertilityRate getter delegates to it (lines 4016–4018).

Parameters.java, lines 1932–1960 constructs this as the projected number of children aged zero in the region divided by the projected number of women between the maternity-age limits, currently 18–49 (constants). The getter multiplies this by 1,000.

The coefficient is therefore applied to a different predictor from the one used in estimation: both the geographical variation and the construction differ. This is not a missing per-1,000 conversion, and switching fertility alignment on or off does not make the two predictor definitions consistent. The size of the effect on validation results needs to be assessed after the intended definition is agreed.

Question and proposed resolution

Should F1 be re-estimated using a consistently defined regional fertility-rate series, as suggested in the meeting, or should Java instead use a national predictor consistent with estimation?

Would it make sense to agree on a common definition for estimation and simulation, including the geographical coverage, age range and timing? If this involves changing the predictor used in estimation, I imagine we would also need to re-estimate F1. I would be happy to help check the resulting consistency between Stata and Java.

Linguagem predominante
Java
Estrelas
26
Forks
38
Merge médio
13h 5min
PRs com merge (30d)
7

Preparar o ambiente

Este projeto não oferece contêiner de desenvolvimento, Dockerfile nem guia de contribuição, então a configuração fica por sua conta: comece pelo README e veja nosso guia da primeira contribuição para os passos gerais.

Primeiros passos

  1. Leia a issue inteira e depois o guia de contribuição do projeto.
  2. Comente na issue dizendo que vai assumir — evita que duas pessoas façam o mesmo trabalho.
  3. Faça um fork do repositório e trabalhe em uma branch.
  4. Abra um pull request que referencie o número da issue.

Mais de simpaths/SimPaths

Todas as issues de simpaths/SimPaths

Issues semelhantes

Mais issues de Java

Receba novas issues na sua caixa de entrada

Um resumo curto de issues do GitHub para quem está começando.