Đôi lời về học thuyết Keynes

Bài viết gần đầy của Cassidy về học thuyết Keynes với tiêu đề “The demand doctor” đã hệ thống lại những vấn đề chính trong học thuyết Keynes. Bài viết cho thấy Cassidy là một người ủng hộ Keynes. Anyway, đây là một bài đáng đọc, cảm ơn Giáo sư Trần Hữu Dũng vì đã đang bài này.

Bài viết đã hệ thống lại các điểm nhấn của Lý thuyết tổng quát của Keynes gồm có: Cầu hiệu quả, số nhân, bẫy thanh khoản, đa điểm cân bằng, tinh thần động vật. Cụ thế:

1. Cầu hiệu quả (Effective demand)

In “The General Theory,” Keynes took aim at this view of the world. His central insight was that the economy was driven not by prices but by what he called “effective demand”—the over-all level of demand for goods and services, whether cars or meals in fancy restaurants. If car manufacturers perceived that the demand for their products was lagging, they wouldn’t hire new workers, however low wages fell. If a restaurateur had vacant tables night after night, he would have no incentive to borrow money and open a new venture, even if his bank was offering him cheap loans. In such a situation, the economy could easily remain stuck in a rut, until some outside agency—the government was Keynes’s favored candidate—intervened and spurred spending. Only then would private businesses be emboldened to expand production and hire workers.

Khác với lập luận của Hayek in “prices and Production” (1931):

“The only way permanently to ‘mobilize’ all available resources is . . . not to use artificial stimulants—whether during a crisis or thereafter—but to leave it to time to effect a permanent cure.”

 2. Số nhân (Multiplies)

 As the Depression deepened, seeming to confirm his warnings, Keynes sharpened his theoretical arguments. In 1933, drawing on an article by his student Richard Kahn, he made the case that one dollar of additional government spending—on a new railway station, say—could ultimately generate two dollars, or even more, in additional output and income. This was the so-called “multiplies” effect. As the unemployed were set to work on public projects, he reasoned, they would spend their wages on other goods and services, which would prompt businesses to take on more workers. Those workers, in turn, would spend more, leading to further hiring, and so on. What’s more, all of these newly employed workers would be paying taxes, which would bring down the budget deficit.

 3. Bẫy thanh khoản (Liquidity trap)

So why didn’t the Obama Administration’s 2009 stimulus package usher in a true recovery? Keynes would have pointed out that, with households and firms intent on paying down debts and building up their savings in the aftermath of a credit binge, large-scale deficit spending is needed merely to prevent a recession from turning into a depression. With interest rates already close to zero, Keynes would have argued that the economy was stuck in a “liquidity trap,” greatly limiting the Federal Reserve’s scope for further action. He would also have noted that the stimulus was—especially compared with the devastation it meant to address—rather small: equivalent to less than two per cent of G.D.P. a year for three years. Even this overstates its magnitude, given that much of the increase in federal spending was offset by budget cuts at the state and local levels. In its totality, government spending didn’t increase much at all. Between 2007 and the first half of this year, it rose by about three per cent in real dollars.

4. Đa điểm cân bằng

Even his great intellectual contribution—the notion that economies can remain in an “equilibrium” state with mass unemployment—defies easy explanation. How exactly does it come about? Not simply because, as textbooks often suggest, prices and wages get “stuck,” maybe asa result of union contracts, Keynes was convinced that, even if wages and prices are flexible, the economy could remath mired. Any economy was capable ofwhat modem economists call “multiple equilibria”; different stable points of functioning, at levels, ranging from penury to prosperity.

5. Tinh thần động vật

The problem isn’t that Wall Street traders are reckless or stupid; Keynes had a wary respect for their smarts. The problem is that our investment choices can never be truly rationalized. “If we speak frankly,” Keynes wrote, “we have to admit that our basis of knowledge for estimating the yield ten years hence of a railway, a copper mine, a textile factory, the goodwill of a patent medicine, an Atlantic liner, a building in the City of London amounts to little and sometimes to nothing.” Keynes distinguished this sort of incalculable uncertainty from quantifiable risk—the risk, say, that your straight flush will be trumped by four of a kind, or that you will be killed at Russian roulette. When you decide to build a factory or take a flyer on the stock market, the arithmetic of probability and rational decision theory provide no real guidance. Such decisions can be taken, Keynes wrote, only as a result of “animal spirits—of spontaneous urge to action rather than inaction, and not as the outcome of a weighted average of quantitative benefits multiplied by quantitative probabilities.”

Bài viết cũng đã chỉ ra một số vấn đề của Keynes, tuy nhiên nổi bật là:

The dutiful Keynesian policymaker must decide on a certain level of borrowing and spending and also on when to withdraw the stimulus. But how much additional demand does it take to make businessmen feel optimistic when they get up  in the morning? And how much debt can be sustained without roiling markets with self-fulfilling anxiety?


Đây cũng là những gợi ý nghiên cứu hết sức thú vị. Nếu các bạn có thời gian, các bạn nên đọc kỹ bài báo này (Download tại đây – Nguồn: THD) và đặc biệt hơn nên đọc Lý thuyết tổng quát về việc làm, lãi suất, và tiền tệ của Keynes.


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