Expense Protection Method

There are two ways to answer "how much income will I need in retirement?".

The income replacement method starts from your salary and assumes you will need a percentage of it — usually 70 to 90 percent.

The expense protection method ignores the salary and starts from what you will actually spend. It identifies the expenses likely in the retirement years, estimates each, and provides for them.

The workbook's verdict on it is balanced: it reflects the individual's real situation, but it is slightly cumbersome because of the detailed listing required — and it is only as good as that list.

The process.

1. Prepare a list of pre- and post-retirement expenses and arrive at the total expense list. The workbook's Table 3.1 groups them under housing, living expenses, medical expenses, transportation and recreational expenses.
2. Typically take post-retirement expenses as a percentage of pre-retirement expenses, on the assumption that some heads, such as transport and home loan EMI, fall away.
3. Add the heads likely to rise — health above all.
4. Inflate the total over the years left to retirement to arrive at the expense in retirement.

The risk. If expenses are overlooked or underestimated, the income required is calculated lower than what is actually needed — and the workbook names the consequence as a risk of overspending in retirement.

Against the income replacement method:

Expense at retirement = Retirement expenses at current prices × (1 + inflation)^(years to retirement)

The workbook's case. Pradeep, 30, spends Rs 50,000 a month, of which 60 percent is household expenses. He retires at 55 and expects additional discretionary expenses of Rs 10,000 a month at current prices. Inflation is 6 percent.

Household expenses carried into retirement = 60% × 50,000 = Rs 30,000
Add discretionary expenses in retirement   =             + Rs 10,000
Retirement expenses at current prices      =               Rs 40,000

Years to retirement = 55 − 30 = 25
Expense at retirement = 40,000 × (1.06)^25 = Rs 1,71,675 a month

Set against the income replacement method. The workbook runs Pradeep through that method too, on different assumptions — current income Rs 10 lakh a year, growing 10 percent, replacement ratio 75 percent:

Income at retirement = 10,00,000 × (1.10)^25 = Rs 1,08,34,706 a year
Income required      = 75% × 1,08,34,706     = Rs 81,26,029 a year
                                              ≈ Rs 6,77,169 a month

The expense protection figure is Rs 1,71,675 a month, about Rs 20.6 lakh a year. The two methods, applied to the same person on the workbook's own inputs, differ almost fourfold — because one starts from a Rs 10 lakh salary growing at 10 percent and the other from Rs 40,000 a month of expenses growing at 6 percent. Which assumption is realistic is the adviser's judgement; the arithmetic simply shows how much rides on it.

Chapter 3, section 3.2.2 (Determine Income Requirement in Retirement), presents the expense protection method alongside the income replacement method, with the Pradeep example for each. Expect the Rs 1,71,675 computation, a question on which method is cumbersome but more tailored, and a question on the consequence of overlooking expenses (overspending in retirement).

• Inflate over years to retirement. 25 years for Pradeep — not the years in retirement, and not his age.
• The Rs 10,000 discretionary expense is at current prices and is added before inflating, not after.
• Only the household share carries over. The workbook takes 60 percent of Rs 50,000, not the full Rs 50,000, because transport and loan EMIs are assumed to fall away.
• Underestimating expenses leads to overspending, not underspending — the income target was set too low.
• The two Pradeep examples use different inputs (monthly expenses versus annual income, 6 percent inflation versus 10 percent income growth). Do not mix numbers between them in an answer.
• Rs 1,71,675 is the figure at the start of retirement only. Expenses keep rising through retirement, which the corpus calculation must allow for.