I’m convinced that there is much inefficiency in the market. These Graham-and-Doddsville investors have successfully exploited gaps between price and value. When the price of a stock can be influenced by a “herd” on Wall Street with prices set at the margin by the most emotional person, or the greediest person, or the most depressed person, it is hard to argue that the market always prices rationally. In fact, market prices are frequently nonsensical.

With [incomplete or] assymetric information [and that's practically always the case]... Stiglitz and Greenwald proved... markets are inefficient, and that should be the default model.

Markets can be efficient or inefficient; so can governments. thus market failure is a counterpoint to government failure.

Even in financial markets, the concept of market efficiency does not hold.

Corruption exists because there is too much, not too little, market.

The pre-1800 pattern of commercial panics had to be a case of NON MACRO-EFFICIENCY of markets. We’ve come a long way, baby, in two hundred years toward micro efficiency of markets: Black-Scholes option pricing, indexing of portfolio diversification, and so forth. But there is no persuasive evidence, either from economic history or avant garde theorizing, that MACRO MARKET INEFFICIENCY is trending toward extinction: The future can well witness the oldest business cycle mechanism, the South Sea Bubble, and that kind of thing. We have no theory of the putative duration of a bubble. It can always go as long again as it has already gone. You cannot make money on correcting macro inefficiencies in the price level of the stock market.

In economics, disbelief in secrets leads to faith in efficient markets. But the existence of financial bubbles shows that markets can have extraordinary inefficiencies. (And the more people believe in efficiency, the bigger the bubbles get.)

First, the key to our prior success had been an inefficient market. The real estate industry had always been fragmented, with valuations and projections that often varied widely.

The Soviet Union and its satellite Socialist countries in Eastern Europe have typically avoided unemployment and business cycles, except as they are induced through their trade with the Western World. But on the other hand they are clearly inefficient and wasteful, at least relative to the West. As repeated statements by the socialist economists themselves make clear, the excessive concentration of economic decision-making is a prime cause of the inefficiency. There are recurring demands for "liberalization," even by the highest authorities (Yuri Andropov, the effective head of the Soviet Union, being the latest example), but they are responded to only mildly or not at all. Clearly, a really major step toward decentralization of economic power, to the plant managers or the workers themselves, is perceived as a threat to the system.

Congress has a deep, vested interest in its own inefficiency.

Corruption often exists because there are too many market forces, not too few.

So far as school education is concerned, many of the assumptions necessary for market efficiency fail, the main problems being imperfect information, imperfect capital markets, and external effects.

I have endured the maddening inefficiencies of the public sector

I was trained on the efficient markets hypothesis, and yet every market that I've seen up close has been anything but.