Why Acquisition Expenses Create Early-Duration Losses
A long-term policy may require substantial expenditure before it has generated much premium income. For example, a hypothetical insurer may pay an issue commission and incur underwriting and setup costs when a policy is issued. If those costs exceed any income at issue, the first entry in the profit signature is negative. Later profits may recover that initial loss, but their contribution to NPV depends on when they emerge and how likely the policy is to remain in force.
The central calculation is to put the acquisition outlay and later expected profits on the same timing basis. In particular, do not treat a profit conditional on a policy remaining active as though it will be received on every issued policy. Also, do not discount an expense paid at issue as if it were paid at the end of the first year.
The profit \(\pi_t\) is net of the premiums, benefits, and expenses assigned to duration \(t\) under the stated profit-test convention. It can be positive or negative. The weight \(w_t\) accounts for the chance of reaching that profit-generating state; it is not an additional discount factor. The discount factor accounts for timing in money terms.
Assume an effective annual discount rate \(i\), with \(v=1/(1+i)\), and assume the later profits emerge at year-ends. The NPV per policy issued is then the sum of the time-0 expense and the discounted expected profits:
This expression uses one consistent basis: all entries are per policy issued, the issue expense is paid at time 0, and the year-\(t\) profit is discounted \(t\) years. If an expense is paid at a different time, it belongs at that time in the signature and must be discounted accordingly. The formula also assumes the stated annual timing; it should not be used unchanged for profits emerging at other times.
Why the Signature Produces the Expected Present Value
The weighting by \(w_t\) follows directly from expected value. Let \(I_t\) equal 1 if the policy is in force at the time the duration-\(t\) profit emerges and 0 otherwise. If the conditional profit is the fixed amount \(\pi_t\), the actual duration-\(t\) profit is \(I_t\pi_t\). Since \(E[I_t]=P(I_t=1)=w_t\), its expected value is \(w_t\pi_t\). Discounting that expected amount gives \(v^t w_t\pi_t\).
More generally, let \(Z_t\) be the random net profit per issued policy at duration \(t\), allowing for possible claims, expenses, or other outcomes. Linearity of expectation gives the same result without requiring profits at different durations to be independent:
Thus the signature entry at duration \(t\) is \(E[Z_t]\), and its discounted sum equals the expected present value under the assumed timing and discount basis. Dependence between the events at different durations does not invalidate this identity; it is the linearity of expectation that matters.
Record an expense of \(A\) at time 0 as the signature entry \(-A\), if it is paid at issue for each policy issued.
For a fixed conditional profit \(\pi_t\), multiply it by the probability \(w_t\) of being in force. Use an expected net amount directly if the duration profit has multiple possible outcomes.
Multiply each end-of-year-\(t\) signature entry by \(v^t\), then add the issue-date expense and all discounted entries.
Worked Examples
Worked Example: An Issue Expense Followed by Uneven Profits
A hypothetical three-year policy has an acquisition expense of $600 paid at issue. Conditional net profits at the ends of years 1, 2, and 3 are $250, $300, and $350 per in-force policy. The probabilities of being in force at those times are \(0.80\), \(0.60\), and \(0.40\), respectively. Use an effective annual discount rate of \(5\%\). Construct the signature and calculate NPV per policy issued.
Method. First calculate each expected duration profit per policy issued, then discount it for its emergence time. The issue expense is not multiplied by a later in-force probability because it is paid for each policy at issue.
At time 0 the signature entry is \(-\$600\). The later entries are:
With \(v=1/1.05\), the discount factors are \(v=0.952381\), \(v^2=0.907029\), and \(v^3=0.863838\), to six decimal places. Therefore:
The NPV is -$125.32 per policy issued, rounded to the nearest cent. The signature entries sum to \(-600+200+180+140=-\$80\) before discounting, so both the undiscounted total and the discounted NPV are negative. The NPV is lower because the positive profits arrive after the issue expense. A common error would be to count each conditional profit in full, ignoring the in-force probabilities; that would overstate the expected profits per issued policy.
Worked Example: How Much Acquisition Expense Can Later Profits Support?
A hypothetical contract has a $450 acquisition expense paid at issue. It produces a conditional net profit of $300 at the end of each of the next three years if still in force. The probabilities of being in force at the respective year-ends are \(0.80\), \(0.60\), and \(0.40\). Assume an effective annual discount rate of \(5\%\). Calculate the NPV, then find the maximum issue-date acquisition expense that would make NPV zero with all other assumptions unchanged.
Method. The expected signature entries at years 1, 2, and 3 are \(0.80(300)=\$240\), \(0.60(300)=\$180\), and \(0.40(300)=\$120\). Using the discount factors \(0.952381\), \(0.907029\), and \(0.863838\):
Subtract the acquisition expense paid at time 0:
To make NPV zero, the issue-date acquisition expense must equal the present value of the later profits. The maximum break-even expense is therefore \(\boxed{\$495.50}\), rounded to the nearest cent. This is a break-even amount for the stated profit and in-force assumptions, not a general value for an acquisition expense.
The timing check is important: the $450 expense is paid at time 0, so it is subtracted without discounting. Discounting it one year would incorrectly use \(450/1.05=\$428.57\) and would produce an NPV of about $66.93, rather than $45.50. That wrong result values a different payment timing.
Worked Example: Comparing Two Persistency Patterns
A hypothetical policy has a $400 acquisition expense at issue and conditional profits of $200, $250, and $300 at the ends of years 1, 2, and 3. Compare two possible in-force probability patterns. Pattern H has probabilities \(0.90\), \(0.80\), and \(0.70\); Pattern L has probabilities \(0.70\), \(0.50\), and \(0.30\). Assume an effective annual discount rate of \(10\%\), and hold the conditional profits and all other assumptions fixed.
Method. For each pattern, weight the conditional profit by its in-force probability, then discount the resulting signature entries. The discount factors are \(v=1/1.10=0.909091\), \(v^2=1/1.21=0.826446\), and \(v^3=1/1.331=0.751315\).
For Pattern H, the expected signature entries are \(0.90(200)=\$180\), \(0.80(250)=\$200\), and \(0.70(300)=\$210\). Thus:
For Pattern L, the expected signature entries are \(0.70(200)=\$140\), \(0.50(250)=\$125\), and \(0.30(300)=\$90\). Therefore:
Under these assumptions, Pattern H has the higher NPV by \(86.70-(-101.80)=\$188.50\), rounded to the nearest cent. The comparison follows because all three conditional profits are positive: a higher probability of being in force increases each expected profit entry. It would not be safe to conclude that greater persistency must always increase NPV. If some later conditional profits were negative, a greater chance of reaching those durations could increase expected losses instead. This example compares specified probability patterns; it does not prescribe how persistency should be estimated.
Interpreting Early Losses and Later Recovery
A negative issue-date entry is not, by itself, evidence of a negative NPV. It shows that the acquisition outlay creates an early loss in the signature. Whether later profits recover that loss depends on their expected amounts, their timing, and the assumed chance of remaining in force long enough to generate them. A contract can have positive undiscounted total profits and still have negative NPV when later profits are too small or too distant.
The following distinctions help keep the calculation interpretable:
- Acquisition expense: an issue-date outflow belongs at time 0 if it is paid at issue. Its contribution to NPV is then \(-A\).
- Expected profit: a profit stated per in-force policy must be weighted by the relevant in-force probability to obtain its expected contribution per issued policy.
- Discounting: after the expected profit has been found, discount it according to when it emerges. In-force weighting and discounting address different questions.
- Sign: a positive conditional profit multiplied by a valid probability remains positive; a negative conditional profit remains negative. Do not reverse the profit sign merely because it is being weighted.
Common Mistakes
- Discounting an issue-date expense: if the expense is paid at time 0, subtract \(A\) directly. Discounting it as a year-end expense changes the cash-flow timing.
- Omitting the in-force weight: a conditional profit is not automatically received on every policy issued. Weight it by the probability of reaching that duration, or use the expected duration profit per issued policy if it is already provided.
- Applying the weight twice: if a supplied signature entry is already an expected profit per issued policy, do not multiply it by an in-force probability again.
- Confusing probability and discount factors: \(w_t\) reflects whether the profit is generated; \(v^t\) reflects when its value is measured. Both may appear in the same term, but they are not interchangeable.
- Assuming persistency always helps: increased in-force probabilities increase positive conditional profits but can also increase the contribution of negative conditional profits.
Check Your Understanding
For each problem, form the expected profit signature before discounting. Unless otherwise stated, the acquisition expense is paid at issue, profits emerge at year-ends, and the discount rate is effective annually.
- A hypothetical two-year contract has a $320 issue expense, conditional profits of $180 and $200, in-force probabilities of \(0.75\) and \(0.50\), and an annual discount rate of \(4\%\). Find its NPV per policy issued. (Answer: -$97.74)
- A hypothetical three-year policy has a $250 acquisition expense and conditional profits of $160, $200, and $200. Its in-force probabilities at the year-ends are \(0.90\), \(0.80\), and \(0.50\). At \(5\%\) interest, calculate NPV per policy issued. (Answer: $118.65)
- At \(10\%\) interest, a hypothetical two-year policy has conditional profits of $220 at each year-end and in-force probabilities of \(0.80\) and \(0.60\). What is the maximum issue-date acquisition expense consistent with zero NPV? (Answer: $269.09)
- A hypothetical policy has a $300 issue expense and conditional profits of $100, \(-$200\), and $400 at the ends of years 1, 2, and 3. The respective in-force probabilities are \(0.90\), \(0.70\), and \(0.50\), and the annual discount rate is \(5\%\). Find NPV per policy issued. (Answer: -$168.50)
- A hypothetical three-year contract has a $400 issue expense, conditional profits of $200 at each year-end, and in-force probabilities of \(0.90\), \(0.70\), and \(0.40\). At \(6\%\) interest, calculate NPV per policy issued. (Answer: -$38.42)