"At will" is vastly insufficient to generate an equality of power.
The masters, being fewer in number, can combine much more easily: and the law, besides, authorises, or at least does not prohibit, their combinations, while it prohibits those of the workmen. We have no acts of parliament against combining to lower the price of work, but many against combining to raise it. In all such disputes, the masters can hold out much longer. A landlord, a farmer, a master manufacturer, or merchant, though they did not employ a single workman, could generally live a year or two upon the stocks, which they have already acquired. Many workmen could not subsist a week, few could subsist a month, and scarce any a year, without employment.
Under the feudal system, lords had at least a nominal obligation to see to the welfare of their charges. I'm not claiming the relationship was otherwise equal, but that sense of obligation is now all but wholly absent.
The masters, being fewer in number, can combine much more easily: and the law, besides, authorises, or at least does not prohibit, their combinations, while it prohibits those of the workmen. We have no acts of parliament against combining to lower the price of work, but many against combining to raise it. In all such disputes, the masters can hold out much longer. A landlord, a farmer, a master manufacturer, or merchant, though they did not employ a single workman, could generally live a year or two upon the stocks, which they have already acquired. Many workmen could not subsist a week, few could subsist a month, and scarce any a year, without employment.
-- Adam Smith, Wealth of Nations http://www.gutenberg.org/files/3300/3300-h/3300-h.htm#link2H...
Under the feudal system, lords had at least a nominal obligation to see to the welfare of their charges. I'm not claiming the relationship was otherwise equal, but that sense of obligation is now all but wholly absent.