Each 10, as we've seen, be whipsawed by markets in just the short term.
Earnings per share were further boosted by lower weighted average shares outstanding, or WASO, and from a lower tax rate, resulting in a 39.4% increase in GAAP earnings per share and a 31.8% increase in adjusted EPS.
Revenues of $711.5 million were up $103.6 million, compared to revenues of $607.9 million in the prior-year quarter.
GAAP earnings per share of $1.77 in 2Q '21, compared to $1.27 in 2Q '20.
Adjusted earnings per share for the quarter were $1.74, which compared to $1.32 in the prior-year quarter.
The difference between our GAAP and adjusted earnings per share in 2Q '21 reflects $3.1 million in a fair value remeasurement of acquisition-related contingent consideration, which increased GAAP earnings per share by $0.09, and a $2.4 million of noncash interest expense related to our convertible notes, which reduced GAAP earnings per share by $0.06.
Net income of $62.8 million, compared to $48.2 million in the prior-year quarter.
SG&A of $133.9 million were 18.8% of revenues.
This compares to SG&A of $126.9 million or 20.9% of revenues in the second year -- in the second quarter of 2020.
Second-quarter 2021 adjusted EBITDA of $92.3 million or 13% of revenues, compared to $75.8 million or 12.5% of revenues in the prior-year quarter.
Our second-quarter effective tax rate of 19.3%, compared to 23.1% in the prior-year quarter.
Without this change, our second-quarter '21 effective tax rate would have been 23.3%.
For the balance of '21, we expect our effective tax rate to be between 22% and 25%.
Fully diluted WASO for Q2 of 35.4 million shares declined 2.5 million shares, compared to 37.9 million shares in 2Q '20.
Our convertible notes had a potential diluted impact on earnings per share of approximately 872,000 shares for the quarter.
Included in WASO, as our average share price of $140.72 this past quarter was above the $101.38 conversion threshold rate.
Billable head count increased by 470 professionals or 10.1% that's compared to the prior-year quarter.
Noteworthy, in May, we closed on our acquisition of The Rhodes Group, welcoming 38 billable professionals to our construction solutions practice within our FLC segment.
And in July last year, we acquired Delta Consulting, adding 151 billable professionals.
Sequentially, billable head count decreased by 27 professionals or half of 1%.
In Corporate Finance & Restructuring, revenues of $231 million decreased 6.1% compared to the prior-year quarter.
Adjusted segment EBITDA of $40.2 million or 17.4% of segment revenues, compared to $76.3 million or 31% of segment revenues in the prior-year quarter.
Adjusted segment EBITDA was negatively impacted by the continued downturn in restructuring activity compared to the record demand that saw in 2Q '20 in the initial wake of COVID as well as higher compensation, primarily related to a 19.8% increase in billable head count.
On a sequential basis, revenue increased $4.8 million or 2.1%, a strong growth in both our business transformation and transactions businesses and related success fees more than offset the continued decline in demand for our restructuring services.
Revenues of $150.7 million increased 41.7% compared to the prior-year quarter.
Adjusted segment EBITDA of $18 million or 11.9% of segment revenues, compared to a loss of $9 million in the prior year quarter.
The year-over-year increase in adjusted segment EBITDA was primarily due to higher revenues and a 14 percentage point increase in utilization, which was partially offset by higher variable compensation and a 5.5% increase in the billable head count.
Sequentially, revenues were flat but adjusted segment EBITDA decreased $11.4 million, primarily due to increased compensation, acquisition-related costs, and certain revenue deferrals.
Our economic consulting segment's record revenues of $183.3 million increased 21% compared to the prior-year quarter.
Our adjusted segment EBITDA of $30.7 million or 16.7% of segment revenues, compared to $21.7 million or 14.3% of segment revenues in the prior-year quarter.
The increase in adjusted segment EBITDA was due to higher revenues, which was partially offset by higher variable compensation and a 9.1% growth in billable head count.
Sequentially, revenues increased $14 million or 8.3%, which was primarily driven by increased demand for financial economics and M&A-related antitrust services.
The adjusted segment EBITDA improved $4.1 million.
In technology, revenues of about $78.6 million increased 67% compared to the prior-year quarter.
Adjusted segment EBITDA of $18.5 million or 23.5% of segment revenues, compared to $6.4 million or 13.7% of segment revenues in the prior-year quarter.
Adjusted segment EBITDA declined $3.1 million sequentially, which was largely due to an increase in SG&A expense.
Revenues in the strategic communications segment of $67.8 million increased 19.2% compared to the prior-year quarter.
Adjusted segment EBITDA of $13.5 million or 19.9% of segment revenues, compared to $10 million or 17.6% of segment revenues in the prior-year quarter.
Sequentially, revenues increased $7.3 million, primarily due to higher demand for corporate reputation and public affairs services.
Adjusted segment EBITDA increased $3.1 million.
We generated net cash from operating activities of $125.6 million, which decreased by $27.4 million, compared to $153 million in the second quarter of 2020.
We generated free cash flow of $105.8 million in the quarter.
Total debt, net of cash, decreased $93.5 million sequentially from $252.8 million on March 31, 2021, to $159.4 million on June 30, 2021.
We now expect revenues will range between $2.7 billion and $2.8 billion, up from our prior range of between $2.575 billion and $2.7 billion.
GAAP earnings per share is now expected to range between $5.89 and $6.39, up from a prior range of between $5.60 and $6.30.
We now expect adjusted earnings per share to range between $6 and $6.50, up from our prior range of between $5.80 and $6.50.
The $0.11 per share variance between earnings per share and adjusted earnings per share guidance for full-year 2021 includes the estimated tax-affected impact of noncash interest expense of $0.20 per share that's related to our 2023 convertible notes and the second-quarter 2021 $0.09 per share gain related to some fair value remeasurement.

Summary:
Revenues of $711.5 million were up $103.6 million, compared to revenues of $607.9 million in the prior-year quarter.
GAAP earnings per share of $1.77 in 2Q '21, compared to $1.27 in 2Q '20.
Adjusted earnings per share for the quarter were $1.74, which compared to $1.32 in the prior-year quarter.
GAAP earnings per share is now expected to range between $5.89 and $6.39, up from a prior range of between $5.60 and $6.30.
We now expect adjusted earnings per share to range between $6 and $6.50, up from our prior range of between $5.80 and $6.50.