Research and development expenses increased for the three months ended September 30, 2022, compared to the three months ended September 30, 2021, primarily due to (i) a $2.7 million increase in personnel-related costs primarily resulting from increases in stock-based compensation expense, headcount, bonus expense, benefit costs, and worldwide merit increases, (ii) a $0.6 million increase in subcontractor expenses primarily related to DFI systems and Cimetrix software, (iii) a $0.1 million increase in facilities and information technology-related costs including depreciation expense, and (iv) a $0.1 million increase in travel expenses.
Research and development expenses increased for the nine months ended September 30, 2022, compared to the nine months ended September 30, 2021, primarily due to (i) a $7.3 million increase in personnel-related costs primarily resulting from increases in stock-based compensation expense, headcount, bonus expense, benefit costs, and worldwide merit increases, (ii) a $1.1 million increase in subcontractor expenses primarily related to CV systems and Exensio and Cimetrix software, and (iii) a $0.5 million increase in facilities and information technology-related costs including depreciation expense, and (iv) a $0.3 million increase in travel expense.
We anticipate our expenses in research and development will fluctuate in absolute dollars from period to period as a result of the size and the timing of product development projects.
Selling, General, and Administrative
| | | | | | | | | | | | | | | | | | | | | | | | |
| | Three Months Ended | | | | | Nine Months Ended | | | | | |
| | September 30, | | Change | | | September 30, | | Change | |
(Dollars in thousands) | | 2022 | | 2021 | | $ | | % | | | 2022 | | 2021 | | $ | | % | |
Selling, general and administrative | | $ | 12,005 | | $ | 9,609 | | $ | 2,396 | | 25 | % | | $ | 32,614 | | $ | 28,482 | | $ | 4,132 | | 15 | % |
As a percentage of total revenues | | | 30 | % | | 33 | % | | | | | | | | 30 | % | | 35 | % | | | | | |
Selling, general, and administrative expenses consist primarily of compensation, benefits and stock-based compensation expense for sales, marketing and general and administrative personnel, legal and accounting services, marketing communications expenses, third-party cloud-services related costs, travel and facilities cost allocations.
Selling, general, and administrative expenses increased for the three months ended September 30, 2022, compared to the three months ended September 30, 2021, primarily due to (i) a $2.2 million increase in personnel-related costs mainly resulting from increases in stock-based compensation expense, headcount, bonus and commission expenses, benefit costs, and worldwide merit increases, (ii) a $0.2 million increase in facilities and information technology-related costs, including third-party cloud-services related costs, (iii) a $0.3 million increase in travel and other expenses, and (iv) a $0.2 million increase in legal fees related to the arbitration proceeding over a disputed customer contract. These were partially offset by a $0.5 million decrease in subcontractor expenses.
Selling, general, and administrative expenses increased for the nine months ended September 30, 2022, compared to the nine months ended September 30, 2021, primarily due to (i) a $4.0 million increase in personnel-related costs mainly resulting from increases in stock-based compensation expense, headcount, bonus and commission expense, benefit costs, and worldwide merit increases, (ii) a $0.4 million increase in facilities and information technology-related costs including depreciation expense, (iii) a $0.4 million increase in third-party cloud-services related costs, and (iv) a $0.2 million increase in travel expenses. These were partially offset by a (i) a $0.7 million decrease in subcontractor expenses, and (ii) a $0.2 million decrease in legal fees related to the arbitration proceeding over a disputed customer contract.
We anticipate our selling, general, and administrative expenses will fluctuate in absolute dollars from period to period as a result of cost control initiatives and to support increased selling efforts in the future.