Slap an exclamation point or two behind the latest unemployment figure — 4.5 percent!! — posted for Butler County.

That’s half a percentage point lower than the September jobless rate of 5 percent, and the lowest jobless rate since well before unemployment peaked at about 8 percent in 2009 and 2010.

The jobless rate isn’t likely to go much lower. In October, there were 96,800 residents working, with 4,500 officially listed as unemployed. That means 95.5 percent of those able and willing to work are doing so.

The newly hired are also paying state and federal income taxes as well as state sales tax — vital revenue flowing into government coffers.

Pennsylvania collected $1.7 billion in General Fund revenue in November, $5.6 million more than anticipated, according to the state Revenue Department. Fiscal year-to-date collections total $10.6 billion, which is $109 million, or 1 percent, above estimate. Corporate income tax also is flowing in at above-budget rates, according to the Revenue Department.

The argument has been made frequently that the jobless figures don’t accurately reflect reality, and that those who have stopped looking for work are not counted. However, the actual numbers don’t support this argument.

Butler County has a net population of 185,476. Of those, 30,600 are age 65 or older — retirement age — and another 45,000 are age 19 and younger. That leaves 109,927 residents of working age. The state Department of Labor and Industry lists Butler County’s work force at 101,400, leaving 8,527 residents who are of working age but — for a variety of reasons — are not part of the work force; they might have given up the job search, or they are physically, mentally or emotionally disabled. This non-workforce population amounts to 7.75 percent of the total work-age population, or 4.6 percent of the total population.

The result is that virtually every Butler County resident who is willing and able to work is already doing so.

There are several potential reasons behind the economic rebound. Chief among them is the Marcellus Shale gas boom, which not only has created a vast number of job opportunities but also has lowered energy costs. Pennsylvania now rivals some OPEC-member nations in energy production, and Butler County is the epicenter of the boom. Virtually every business benefits from the lower energy costs.

To a lesser extent, the end of uncertainty over health care issues has prompted many employers to proceed with new hirings. Stability has returned to the health care market, not only with the implementation of the Affordable Care Act, but also with the “divorce” of UPMC and Highmark settled.

The rebound could signal the end of an employers’ market and the start of an employees’ market. Emphasis could be on better training, higher wages and better benefits as employers strive to attract and retain the best workers.

By the same token, many of these employees will be expected to remain drug-free. That could put a sharp dent not only in the area’s illegal drug trade but also in the crimes associated with drugs.

All told, we appear to be on a rising tide of economic prosperity — a tide that lifts all boats. That’s worthy of celebrating, just in time for Christmas.