| > we're assuming that we're operating in an efficient market Arbitrage is, by definition, the refutation of a strong-form efficient market [1]. > liquidity risk, counterparts risk The presence of these risks betrays the absence of a true arbitrage. A pure arbitrage involves simultaneous execution, thereby negating liquidity risk. It also involves instantaneous settlement, thereby negating counterparty risk. In the real world, I've only seen it in specialized real-time foreign exchange and money markets. The risk you can't get rid of is the "risk-free" risk. If the U.S. government blows up, you will not make money on your triangular arbitrage [2]. > analytically evaluate all sources of risk, compare it to the expected profit, and if the latter is no greater than the former, deduce that we are in an efficient market This is an interesting area of theoretical finance [3]. It is practically useless. There is no list of "all sources of risk," much less any way to price it. [1] https://www.investopedia.com/terms/s/strongform.asp [2] https://en.wikipedia.org/wiki/Triangular_arbitrage [3] https://en.wikipedia.org/wiki/State_prices |
Incidentally, [3] is very close to my field of research back when I was doing postgraduate studies in economics, but as you mention, it has close to zero applicability.