The Data Space

Input data shared by every by-contract projection.

The four input CSVs are read here, once per model, and referenced from Projection as data. Projection is parameterized by point_id, so each Projection[N] is a separate ItemSpace with its own cells cache; if the readers lived there, every model point would re-read every file. Holding them in an unparameterized Space reads each file once no matter how many contracts are projected.

Inputs are external files: plain CSVs in the model folder’s parent directory, products/immediate_annuity/, rather than data stored inside the model. The model folder therefore holds nothing but formulas — no _data/, no IOSpec, no embedded values — so a diff of the model shows logic changes only. This follows annuallife.TradLife_A; contrast basiclife.BasicTerm_S, which keeps its inputs inside the model through modelx’s IOSpec machinery.

The consequence worth knowing: the model is not portable on its own. Copying the SPIA_US_S folder without its parent’s CSVs produces a model that reads and then fails on first evaluation.

input_dir() resolves the directory from _model.path.parent at run time, so the model works wherever the repository is checked out. Each table has a filename Reference and a reader Cells:

Reference	Cells	File
model_point_file	model_point_table()	model_point_table.csv
mort_table_file	mort_table()	mort_table.csv
improvement_scale_file	improvement_scale()	improvement_scale.csv
surr_charge_file	surr_charge_table()	surr_charge_table.csv

The two mortality tables are keyed by (age, sex) and the surrender-charge table by policy_year. They are separate files on purpose: the technical notes require the best-estimate basis to be the 2012 IAM Basic table projected with Projection Scale G2, two distinct objects with distinct provenance, and neither may be embedded in the model — the shipped tables are illustrative [std] stand-ins. To swap in a licensed basis, replace mort_table.csv with a same-schema file, or point mort_table_file at a different name, then clear the cache. No formula changes. The improvement scale is swappable the same way, which is how the notes’ first sensitivity — a 50% / 150% scaling of tabulated improvement — is run.

Cells Descriptions

input_dir()

The directory holding the input CSVs: the model folder’s parent.

Inputs are external files, not data stored inside the model, so the model folder is pure formulas. The path is resolved at run time from where the model was read, following annuallife.TradLife_A.

model_point_table()

The model point table, read from model_point_table.csv.

mort_table()

The base annuitant mortality table by age and sex, read from mort_table.csv.

improvement_scale()

The generational improvement scale by age and sex, from improvement_scale.csv.

surr_charge_table()

The commutation surrender-charge scale by contract year, from surr_charge_table.csv.