Now hoverbikes, in contrast strike me as more likely to increase worker marginal productivity all the way down the income ladder.

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The upsides would be that workers may better learn about their marginal productivity, and it could thus lead to more efficient allocations of labor.

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That increased productivity enables workers to earn higher wages, as wages in a competitive market equal the marginal productivity of labor (what the worker adds to production).

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Second, scientific advance tends to have increasing returns to scale: adding more scientists to a community does not diminish individual marginal productivity but tends to increase it.

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Lowering the top marginal rate would encourage additional productivity.

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If you are persuaded that productivity thrives with a lower marginal tax rate, you will agree this approach can help grow the economy and reduce unemployment.

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Moreover, Italy's strong employment record has a downside: zero or even negative productivity growth (see chart 4), as more marginal and less productive workers have been brought into the workforce.

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