In his Jan. 9 letter to the editor (“Mayor’s minimum-wage idea ignores laws of economics”), Porter D. Leighton demonstrates an ample knowledge of economic theory, but his conclusions are unrealistic.

He challenges Portland Mayor Michael Brennan’s proposal that the city establish a minimum-wage ordinance and asks, “Can it be that ‘Hizzoner’ has never taken Economics 101, or is he pandering to economic illiteracy to score political points?”

Mr. Leighton then states that “Economists of every political stripe agree that the general wage level can only be raised by increased marginal worker productivity.” Be that as it may, this theory is not reflected in the real world.

According to “The Top 10 Charts of 2014” on the Economic Policy Institute website, increased marginal worker productivity has risen a staggering eight times faster than general wages since 1979. (This conclusion is based on an EPI analysis of data from the Bureau of Labor Statistics and Bureau of Economic Analysis.)

If “the general wage level can only be raised by increased marginal worker productivity,” as Mr. Leighton suggests, then wage earners are in deep trouble because it is not working. Something must be done.

Raising the minimum wage would put money in the pockets of low-wage workers, who will spend it. This would give working families and the overall economy a boost and lead to the creation of more jobs.

According to Robert Reich, labor secretary to President Clinton, when the minimum wage was raised in 1996, it led to more job gains over the ensuing four years than in any comparable period in American history.

Economics is not physics. Theories like those proposed by Mr. Leighton don’t put food on the tables of working families, but policy changes addressing these real-world problems, like those Mayor Brennan is proposing, will – and they are long overdue.

Robert J. Seeber