We conduct business using a variety of currencies, but we report our results in U.S. dollars. As a result, the volatility of currencies against the U.S. dollar may positively or negatively impact our results. This volatility can make it more difficult to perform period-to-period comparisons of the reported U.S. dollar results of operations, because such results may indicate a growth or decline rate that might not have been consistent with the real underlying growth or decline rates in the local operations. Consequently, we provide information about the impact of foreign currencies in the period-to-period comparisons of the reported results of operations in our discussion and analysis of financial condition in the Results of Operations section below.
Transactional-based fees, that are impacted by the size and timing of our clients' transactions, from real estate investment banking, capital markets activities and other services within our RES businesses, and LaSalle, increase the variability of the revenue we earn. The timing and the magnitude of these fees can vary significantly from year to year and quarter to quarter, and from region to region.
Historically, our quarterly revenue and profits have tended to increase from quarter to quarter as the year progresses. This is a result of a general focus in the real estate industry on completing or documenting transactions by calendar year-end and the fact that certain expenses are constant through the year. Historically, we have reported a relatively smaller profit in the first quarter and then increasingly larger profits during each of the following three quarters, excluding the recognition of investment-generated performance fees and realized and unrealized co-investment equity earnings and losses (each of which can be unpredictable). We generally recognize such performance fees and realized co-investment equity earnings or losses when assets are sold, the timing of which is geared toward the benefit of our clients. Non-variable operating expenses, which we treat as expenses when incurred during the year, are relatively constant on a quarterly basis.
A significant portion of our Compensation and benefits expense is from incentive compensation plans, which we generally accrue throughout the year based on progress toward annual performance targets. This quarterly estimation can result in significant fluctuations in quarterly Compensation and benefits expense from period to period. Consequently, the results for the periods ended September 30, 2017 and 2016, are not fully indicative of the results we expect to realize for the full fiscal year.
RESULTS OF OPERATIONS
We define market volumes for Leasing as gross absorption of office real estate space in square feet for the U.S., Europe and selected markets in Asia Pacific. We define market volumes for Capital Markets as the U.S. dollar equivalent value of investment sales transactions globally.
We have reclassified certain prior year amounts to conform to the current presentation. Specifically during 2017, we revised our methodology for allocating overhead expenses and certain costs associated with our facilities management platform in EMEA to our reporting segments. Prior year amounts have been reclassified to conform to the current presentation. Reclassifications have not been material and have not affected reported net income or consolidated results.