In feudal and ancient economies, 'hiring' and 'firing' did not exist - slaves, unfree peasants/serfs, all of these classes worked...or just died. If there was a low yield year (these are principally agricultural societies), people were not unemployed, they ate less or died. The land owners did not 'fire' them. Land owners themselves could not be 'unemployed' - they owned the means of economic production (land) with no likelihood of displacement except possibly by war. If production fell, the proceeds such as there still were meant he would eat and live.

'Combating unemployment' is the product of wage-labour of capitalism which requires a pool of flexible labour 'governed' by production levels. In 'down-sizing' (farming, manufacturing, service industry) people are fired and then either hired on elsewhere, or live from proceeds of government or families and friends.

See Karl Marx, the later chapters of Das Kapital.

I'm in the middle of packing up for a move so I don't have my books on hand to adequately source (they are literally in boxes right now), however I can tell you that there was a concept of borrowing money and a problem of debtors and unemployment in the late Republic era of Rome.

A major factor in Julius Caesar's need to stay Consul was his immunity to prosecution. His Gallic Wars, his conquests, his dumping of the slaves into Rome, his entire career was essentially run on the Kevin Smith model of "get a bunch of credit cards, max them out, hope my movie sells", but gambling in the political arena of ancient Rome was eminently more dangerous than gambling in the independent film industry.

Money lenders had a virtually limitless power to to impose and demand interest on unreasonable terms, which was an interesting and delicate balance to try to keep people from over relying on these money lenders. In addition to enemies that wanted to arrest him for simple politics, he also owed a ridiculous amount of money to people back in Rome and in an attempt to satisfy that he did a number of questionable things, such as milk his own gubernatorial province dry.

This itself was already established relatively recently as a major problem, seeing as one Gaius Verres had just entered exile for his personal extortion of Sicily. You can read the exact case against Verres on wikisource here.

Therefore when Caesar returned to Rome he was faced with rapacious money lenders and the issue of battle hardened legions that were no longer entirely necessary, many of whom were now at the tail end of their required ten years of service and were ready to re-integrate with the populace of Rome. The issue was that freedmen and plebeian citizens were struggling with work due to the sheer volume of slaves that Caesar had sent back from Gaul, made none the easier by the skilled laborers of the Roman legions entering the work force.

It forced Caesar to have to address the issue of a declining ability by plebeians to find work or pay for grain, greatly influencing his pro-plebeian legislations (you decide if this was out of the goodness of his heart or the practicality of currying favor with the lower classes), and his debt reforms upon his return from Gaul and the Civil War.

What Romans needed to combat wasn't unemployment in general. This tends to matter more in a democratic government where the unemployed also vote, although certainly mob anger in the city of Rome itself could be a major political factor.

What the Roman government needed to combat was unemployment and lack of pay amongst the soldiers, as those soldiers could be readily "re-hired" for purposes contrary to the current leadership of the state, whether it be in the form of brigandage, rebellion, or civil war.

In lieu of borrowing against the future, they "used" inflation by devaluing the coinage in order to secure more money. I say "used" because it wasn't a conscious choice on their part because they didn't have a firm understanding of inflation.

But taken this way, inflation can be seen as an addition form of taxation. The Roman leadership needed to appear to constantly be raising the pay of Roman soldiers in order to keep their loyalty, but with no additional sources of revenue. So by inducing inflation through coin devaluation (remember too this actual mechanism is unknown to them, they just thought they were literally making more money) they could be seen as constantly giving the soldiery their raises, even though in reality they were merely keeping up with inflation so that the soldiers would still have the same purchasing power as previous. What happened is that everyone else's purchasing power was decreasing with their fixed wages and inflation. Thus the state was manipulating the currency so as to place more of the financial burden on everyone else other than the soldiers, which could be seen as an alternate form of taxation to everyone else.

Why go through all this trouble? Because optics matter. Rampant inflation can be blamed on merchant vendors who sell the goods. But increased taxation is blamed on the state.

This vicious circle only really abated when the previously more inefficient means of collecting taxes by farming them out to local collectors was replaced by Diocletian's far more effective taxation in kind system which also indicated the tax liabilities of down to the village level.

But that was simply a more efficient form of taxation in a more systematic, less arbitrary way and with real commodities rather than money. It doesn't solve the problem of what happens if you no longer have enough real commodities to exchange for the amount of military service you need, which is precisely why the Vandal takeover of Africa was so ultimately destructive to the ability of the western empire to pay and maintain its troop levels in the 5th century, which one could argue lead to western imperial collapse.

Sources:

• Williams, Stephen. Diocletian and the Roman Recovery. New York: Methuen, 1985.

• Wickham, Chris. Framing the Early Middle Ages: Europe and the Mediterranean 400-800. Oxford: Oxford UP, 2005.