Reporting concepts
Straight-line and graded expense attribution
Compare straight-line and graded attribution of stock compensation expense over a four-year award, with a worked schedule and the effect on early periods.
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The same cost, spread differently
Attribution is the question of when a fixed grant-date cost is recognized, not how large it is. Both conventions recognize the same total for an award that vests in full; they disagree about how much belongs to the early periods.
- Straight-line spreads the award’s cost evenly over the service period to the last vesting date.
- Graded treats each vesting tranche as its own award and recognizes it over its own, shorter service period.
Because early tranches vest sooner, graded attribution loads more expense into the first periods. Under US GAAP, an award with graded vesting may be attributed either way as a policy choice, and a straight-line policy still has to recognize at least the value of the portion that has actually vested.
Work through a four-year award
Assume 40,000 restricted stock units granted January 1, 2024, vesting monthly over four years with a one-year cliff, with a recorded grant-date fair value of $2.00 per unit. The grant-date cost is 40,000 × $2.00 = $80,000 under either convention, and the final vesting date is January 1, 2028.
| Through | Straight-line | Graded | Difference |
|---|---|---|---|
| December 31, 2024 | $19,986 | $47,050 | $27,064 |
| December 31, 2025 | $39,973 | $67,306 | $27,334 |
| December 31, 2026 | $59,959 | $77,050 | $17,091 |
| December 31, 2027 | $79,945 | $79,999 | $54 |
| January 1, 2028 | $80,000 | $80,000 | $0 |
The straight-line figures are the $80,000 prorated over the 1,461 days from grant to full vesting: $80,000 × 365 ÷ 1,461 = $19,986 after the first year. The graded figures are the sum of each tranche’s own progress: the cliff tranche alone contributes about $19,945 of the first year, because it is a $20,000 cost recognized over a single year.
By the fourth year the two conventions have nearly converged, which is the general shape: graded attribution front-loads expense and straight-line defers it, and the difference is largest in year one.
What a forfeiture does to the schedule
When unvested units are forfeited, previously recognized cost attributable to them is reversed in the period of the forfeiture. That can produce a negative expense for the period, which is a reversal rather than an error. Cost attributable to units that already vested is not reversed, and the expiration of a vested, unexercised option is a different event with a different treatment.
Unrecognized cost and the remaining recognition period are read the same way under both conventions: what is left to recognize, and how long it has to run. Under graded attribution that period is a weighted average across the tranches still recognizing.
Choose the policy before running the report
Attribution is an accounting policy applied consistently, not a setting to move between periods to reach a number. Set it with the person responsible for the financial statements, alongside expected volatility, the risk-free rate, the expected term, and the fiscal year end.
In the stock compensation report, the assumptions are company-level and reports rebuild from the current ones, so retain the reviewed export with the assumptions that produced it. The report covers the app’s supported award types and conventions, not every arrangement, modification, or performance condition in ASC 718.