New Asset Performance Report

[Carsten Rinke]

Hi,

I have written a report that gives me an idea how good some of my 
financial products are performing, see the draft version of a usage 
description below.

Two questions to this:

a) anyone volunteering to test it? (including giving suggestion for an 
improved usage description)

b) what is the best way to share it?
I would a assume utilizing a wiki page for that purpose, attaching the 
scheme code to it for download.
Any better alternatives?

Thanks for any help and advice in advance,
Carsten


      Usage (draft)

This Report is intended to measure the performance of asset accounts. 
The main idea is to visualize the performance of financial programs like 
life insurances or fonds based saving plans in comparison with simple 
saving accounts. Nevertheless, this report can be run against any account.

The performance is measured as interest rate that should have been 
applied to an imaginary savings account leading to the same result as 
shown by the selected real account. There are two measurements included 
in this report: One on a per year basis, omitting the history of 
previous years, and the other one including the history from start of 
the performance measurement time period until the year of evaluation, 
called accumulated result (accumulated over several years).

The per-year-result (yearly result) evaluates each year of the 
measurement time period in an isolated view. Each year has a balance at 
the beginnging of the year, a balance at the end of the year, and 
deposits into the selected accounts throughout the year. The exact time 
of the deposits will be discarded, instead, it is assumed that the 
deposits have been done on a monthly basis with the average value (total 
deposit / 12 ). The result of this measurement is the calculated 
interest rate of a simple savings account with the same performance.

Example: Only one account is selected, the measurement period has been 
adjusted to span over only one year. The starting balance at the 
beginning is 100, in April 200 have been dosited, in October 140 have 
been withdrawn, and one year after the beginning of the measurement 
period the balance is 110. The algorithm tranlates the deposits and 
withdrawals into a total deposit of 60 (=200-140) split into 12 monthly 
deposits of 5. In this example the total of the balance at year start 
(100) plus the total deposits (60) are greater then the balance at year 
end (110), meaning that a corresponding saving account has a negative 
performance with a negative interest rate, i.e. instead of receiving 
interest fee payments have been made.

The accumulated result takes all years before the year of evaluation and 
the year of evaluation into account. Deposits within of all the years up 
to the year of evaluation are split into equally large deposits per 
year. The resulting interest rate applies for all years from the start 
of the measurement period until the current year of evaluation.

Example: Only one account is selected, the measurement period has been 
adjusted to span over two years. The starting balance at the beginning 
is 100, in April of the first year 200 have been dosited, in October of 
the second year 140 have been withdrawn, one year after the beginning of 
the measurement period (end of first year) the balance is 110, at the 
end of the second year the balance is 180. For the first year, the 
algorithm assumes that a deposit of 200 has been done at the beginning 
of the year, so the interest will be calculated on a starting balance of 
300 (=100+200). With a year-end balance of 110 the performance value 
will be negative, in fact almost the whole deposit of this year has been 
lost giving a corresding negative result for the first year. For the 
second year, the algorithm sees a total deposit of 60 (=200-140) and 
assumes that 30 of those have been available at the start of the first 
year, and the other 30 at the beginning of the second year. The 
resulting interest that is valid for both years is based on three parts: 
Interest paid on the starting balance of 130 (100+30) for the first 
year, interest paid for the result reached until the beginning of the 
second year (130 + (interest on 130) ), and finally interest on the 
second year's deposit of 30. The interest rate is the same for all three 
parts and the algorithm finds the suitable interest rate that leads to 
the final balance of 180.

NOTE: Deposits must come from a BANK account (meaning, accounts that 
have been set to type BANK in GnuCash). This is to cover the case that 
you get e.g. payments from the state into the selected account as for 
public subsidized programs like old age pension saving plans, and which 
should be booked in corrsponding income accounts. Only payments from the 
bank accounts are seen as personal contribution, and payments from 
outside the bank accounts are treated as additional interest payments.