Table:
| ($ in millions) |  |  |  |
| --- | --- | --- | --- |
| For the year ended December 31: | 2019 | 2018 | Yr.-to-Yr. Percent Change |
| Selling, general and administrative expense |  |  |  |
| Selling, general and administrative—other | $17,099 | $16,438 | 4.0% |
| Advertising and promotional expense | 1,647 | 1,466 | 12.3 |
| Workforce rebalancing charges | 555 | 598 | (7.2) |
| Amortization of acquired intangible assets | 762 | 435 | 74.9 |
| Stock-based compensation | 453 | 361 | 25.2 |
| Bad debt expense | 89 | 67 | 32.5 |
| Total consolidated selling, general and administrative expense | $20,604 | $19,366 | 6.4% |
| Non-operating adjustments |  |  |  |
| Amortization of acquired intangible assets | (762) | (435) | 74.9 |
| Acquisition-related charges | (282) | (15) | NM |
| Operating (non-GAAP) selling, general and administrative expense | $19,560 | $18,915 | 3.4% |
Paragraphs:
Selling, General and Administrative Expense
NM—Not meaningful
Total selling, general and administrative (SG&A) expense increased 6.4 percent in 2019 versus 2018, driven primarily by the following factors: • Higher spending (5 points) driven by Red Hat spending (5 points); and • Higher acquisition-related charges and amortization of acquired intangible assets associated with the Red Hat acquisition (3 points); partially offset by • The effects of currency (2 points).
Operating (non-GAAP) expense increased 3.4 percent year to year primarily driven by the same factors excluding the acquisition-related charges and amortization of acquired intangible assets associated with the Red Hat transaction.
Question:
What caused the Operating (non-GAAP) expense to increase?
Answer: driven by the same factors excluding the acquisition-related charges and amortization of acquired intangible assets associated with the Red Hat transaction.