The Data Space

Input data shared by every by-contract projection.

The seven 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/fixed_deferred_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 MYGA_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
surr_charge_file	surr_charge_table()	surr_charge_table.csv
surr_charge_age_cap_file	surr_charge_age_cap_table()	surr_charge_age_cap.csv
rate_scenario_file	rate_scenario()	rate_scenario.csv
withdrawal_file	withdrawal_table()	withdrawal_table.csv
mva_factor_file	mva_factor_table()	mva_factor_table.csv

Three of these carry a compound key. surr_charge_table is indexed by (schedule, contract_year) so the initial 9/8/7/6/5 schedule [S10] and the renewal 5/4/3/2/1 schedule [S2] sit in one file; rate_scenario by (scenario_id, t), read as a step function of t, and withdrawal_table by (wd_schedule_id, t), an exact-key lookup, so a scenario or a withdrawal programme is a handful of rows rather than one row per month. In both, t is the model’s 0-based policy month: t = 0 is the first month, and a row keyed t = 12 is the first month of contract year 2.

To swap in a licensed mortality basis — the 2012 IAM Basic table with Projection Scale G2 and the VM-22 Table 6.7 factors that the notes prescribe and that may not be redistributed here — 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.

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()

Annual mortality by attained age and sex, read from mort_table.csv.

surr_charge_table()

Surrender charge rates by schedule and contract year, from surr_charge_table.csv.

surr_charge_age_cap_table()

The attained-age cap on the renewal surrender charge, from surr_charge_age_cap.csv.

rate_scenario()

The exogenous rate scenarios, read from rate_scenario.csv.

Indexed by (scenario_id, t), t the 0-based policy month, and read as a step function of t: each row states the MVA reference yield and the market competitor rate that hold from that month until the next row of the same scenario, so a flat path is one row at t = 0.

withdrawal_table()

Scheduled gross withdrawals, read from withdrawal_table.csv.

Indexed by (wd_schedule_id, t), t the 0-based policy month; a month with no row takes no withdrawal. The worked example’s $4,000 sits at t = 12, the first month of contract year 2.

mva_factor_table()

The declared-differential MVA duration factors, from mva_factor_table.csv.