Pronatalism can be a strategy for longtermism, it's not the only one, and there are arguments against it. Longtermism focuses on the vast future, considering the potential of future generations and possible existential risks. Pronatalism is concerned with increasing the number of people born now. These are two distinct areas, though they can intersect.
In the short-term, unconditional cash transfers deliver bigger bang for the buck than the various policy interventions to increase fertility,
In terms of the change in Household Income Per Impacted Child (5% discount rate, 2019 dollars), Cash transfers appears to be more impactful than all of:
- Unconditional Cash Transfer benchmark: $6,758 to $20,157
- 👎Providing child benefits (which can even have a negative impact): -$41,977 to $18,411
- 👎Increasing maternity pay: $1,296 to $53,476
- 👎Implementing tax benefits: $1,500 to $26,721
- 👎Housing Costs: $62,916
- 👎 Reducing childcare costs: $8,930 to $48,368
Analysis based on the Studies on the Pronatalism Spreadsheet (not mine): https://docs.google.com/spreadsheets/d/1rG74z2tUWm2NAsDCvq87UIgjqFI7lU9iQWwNfh3_0iY/edit#gid=0.
If I look in your spreadsheet the negative impact appears to come from limiting the benefit, i.e. reducing it (quote below). So providing it was presumably positive?
Can you say more about what your "Household Income Per Impacted Child" metric is? Searching online, I only see it in this post and the linked spreadsheet.