facilities and information technology costs. Additionally, payments received from the JDA agreements are treated as credits to research and development expenses.
Research and development expenses for the three months ended March 31, 2023 increased $4.4 million, or 109%, to $8.5 million, compared with $4.1 million for the three months ended March 31, 2022. The increase primarily resulted from a $2.3 million increase in personnel costs mainly attributable to our growth in headcount in support of our ongoing research and development efforts for battery cell development, which included $1.2 million of stock-based compensation expense that primarily relates to restricted earnout shares issued as part of the Business Combination transaction in February 2022 and RSUs and PSUs issued in April 2022. Further, there was a $1.3 million increase in facility costs due to utilities and depreciation expenses, a $1.1 million increase in expenses for lab consumables and material supplies, and a $1.0 million increase in software development costs related to our advanced AI software and BMS. The remainder of the increase was attributable to immaterial other spend. These increases were partly offset by $1.5 million of increased credits to research and development expenses, which are amounts invoiced pursuant to the JDAs. Lastly, there was a $6.8 million decrease in non-recurring facility set-up expenditures in the prior year period, which were offset through reimbursements pursuant to a JDA mentioned above.
General and Administrative
General and administrative expenses consist primarily of costs incurred for salaries and personnel-related expenses, including bonus and stock-based compensation expense, for our finance, legal and human resource functions, expenses for director and officer insurance, outside contractor and professional service fees, audit and compliance expenses, legal, patent related costs, accounting and other advisory services, as well as allocated facilities and information technology costs including depreciation. Upon commencement of commercial operations, we also expect to incur customer and sales support and advertising costs.
General and administrative expenses for the three months ended March 31, 2023 decreased $2.0 million, or 13%, to $13.1 million, compared with $15.1 million for the three months ended March 31, 2022. This decrease primarily resulted from a $4.6 million decrease in transaction costs incurred as a result of the Business Combination during the first quarter of 2022 and a $0.4 million decrease in fees related to marketing and public relations for the Company. These decreases were partially offset by a $2.6 million increase in personnel costs mainly attributable to our growth in headcount to support our operations as a public company, which included $2.0 million of stock-based compensation expense that primarily relates to restricted earnout shares issued as part of the Business Combination transaction in February 2022 and RSUs and PSUs issued in April 2022. Further, there was a $0.7 million increase in professional fees and outside services primarily associated with external consulting, legal, and audit fees.
Non-Operating Items
Interest Income, Net
Interest income primarily consists of interest earned on our cash and cash equivalents and marketable debt securities, which are primarily invested in money market funds and U.S. treasury securities, and accretion income from the U.S. treasury securities.
During the three months ended March 31, 2023, we had interest income of $4.1 million compared with an immaterial amount for the three months ended March 31, 2022. The $4.1 million increase was primarily due to a change in our investment strategy during the fourth quarter of 2022, which resulted in an increased amount of our cash being invested in higher yielding U.S. treasury securities and due to higher interest rates in the current period compared to the same period last year.
Change of Fair Value of Earn-Out Liability, Net
During the three months ended March 31, 2023, we incurred a gain of $0.6 million associated with the change in fair value of the Sponsor Earn-Out Liability compared with a loss of $7.7 million for the three months ended March 31, 2022. With the fair value of the Sponsor Earn-Out Liability tied to the Company’s stock price, continued volatility in the stock price could result in further gains or losses resulting from the change in fair value. Refer to “Note 8 – Sponsor Earn-Out Liability” to the condensed consolidated financial statements for additional information.
Other (Expense) Income, Net
During the three months ended March 31, 2023, we had other income of $0.8 million, compared with other expense of $0.2 million for the three months ended March 31, 2022. The $1.0 million increase in other income was primarily the result of a gain on equity investments and unrealized and realized foreign currency gains due to the strengthening of the U.S. dollar compared with the Chinese renminbi (RMB) and South Korean won (KRW).