The Data Space

Input data shared by every by-policy projection.

The three 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 policies are projected.

Inputs are external files: plain CSVs in the model folder’s parent directory, products/with_profits/, 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 WP_UK_A 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
lapse_table_file	lapse_table()	lapse_table.csv

Note how little is in a file. The discretionary scale that actually drives this product — the bonus rates, the smoothing cap, the target corridor, the guarantee-fill target, the charge levels — lives in model point columns and Projection References rather than in a rate table, and that is not an oversight: none of it is published. Firms’ principles and practices documents describe the discretion and withhold the numbers, so every one of those values is a standardization, and putting them where a reader trips over them is better than filing them in a table that looks like data.

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 annual mortality rates by sex and age, from mort_table.csv.

A [std] proxy shaped like the ONS national life tables, which are the only freely redistributable UK mortality source; CMI tables issued after March 2013 are restricted to Authorised Users, so no current insured rate can be reproduced here. Projection.mort_be_factor carries the allowance for population mortality being heavier than insured experience. Sorted on read, because Projection.mort_rate indexes into it.

lapse_table()

The base annual surrender rates by chassis and policy year, from lapse_table.csv.

Flat on the bond chassis and duration-declining on the endowment. Both are [std] drafting constructions - no public UK with-profits lapse experience was retrieved - and the dynamic multipliers layered on them in Projection.surr_rate matter more than the levels do, because anti-selective exit when guarantees are in the money is the dominant behavioural risk on this product.