The FALSE THEORY that higher wages drive up demand and "stimulate" the economy.
A need to reduce the wealth gap should not include the phony demand for higher wages = populism and demagoguery. Preaching to the idiot masses what they want to hear is popular and wins applause, but is not sound economics.
The Patriotic Millionaires have a website that explains more about why they want to pay higher taxes.
https://patrioticmillionaires.org/our-values/
We believe that the trend of growing economic inequality is both bad for society and bad for business. We believe revenue models that rely on human misery should be exorcised from our economy. We believe the government should mandate a livable wage for all working Americans, rather than relying on “the market” which has failed to realize that goal over 240 years of American history. We believe a national “living wage” law will ensure a stable level of aggregate demand, which will fuel our economy more broadly, ushering in a new era of prosperity for all Americans, including rich ones.
This theory of higher wages to create demand and "fuel" the economy was tried in the 1920s. It wasn't "minimum wage law" yet, but the dogma that wages must be higher in order to increase workers' demand was practiced in the 1920s (for the first time ever in history):
Workers shared in the prosperity of the 1920s, although labor lagged behind business in reaping the benefits of technology. Business supported higher wages as a way to increase workers' buying power. With a shorter workweek (five full days and a half day on Saturday), many workers had more leisure time; large firms such as International Harvester offered employees two weeks of paid vacation a year. But scientific management techniques, first put forth in 1895 by Frederick W. Taylor but only widely implemented in the 1920s, reduced labor's control over the work environment.
-- America's History, Worth Publishers, New York, 1997; p. 745.
There is no theoretical basis for this higher-wage dogma, nor is there any empirical evidence that propping up the wage level to create more demand ever produced any net economic benefit. Rather, the evidence is that this higher-wage dogma helped turn the 1930s recession into the worst depression in history.
In addition to direct higher wages paid to workers, there were two other factors of the 1920s done in order to boost wages above "market" level: protectionism and restriction on immigration.
The increase in protectionism in the 1920s was the greatest or second greatest increase in U.S. tariffs historically, culminating in the Smoot-Hawley tariff increase in the early 30s. This was done to protect U.S. workers against competition from cheap foreign imports, which would put downward pressure on U.S. wages.
And the new crackdown on immigration also was done in order to protect U.S. workers from competition, by restricting increases in the labor supply due to immigrants entering and "stealing" jobs from red-blooded Americans.
So in the 1920s the effort was made to implement this dogma of higher wages, by increasing the wage level artificially above the "market" level, and by protecting workers from foreign imports, and by protecting them from competition from immigrants. So, what was the result of adopting the higher-wages dogma? What should have been a normal stock market crash followed by a typical recession in 1929-30 or -31, what we got was the Great Depression.
In addition to this empirical evidence, there is no logical theory why driving up the wage level should lead to anything but bad consequences. It contradicts the law of supply-and-demand which sets the prices/values at the point where the supply and demand curves intersect, at the lowest level at which workers will offer their labor and the highest level employers must pay in order to attract the needed labor.
Artificially boosting the price of anything, including wages, only leads to higher cost of production and thus higher prices consumers must pay. These higher prices then drive down the demand, thus offsetting any higher demand caused by higher wages.
If there is an inequality of wealth needing to be corrected, the correction is not to artificially drive up the wages, or the labor cost, which only hurts all consumers. Rather, the correction needed is some form of higher taxes on the wealthy and lower taxes on the middle- and lower-income levels.
Restricting competition in any form, including wage competition, can only make the overall economy worse, by the damage it inflicts onto the entire population = all consumers.