reglas del concurso sobre bellezas beauty contest

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reglas del concurso sobre bellezas
(beauty contest)          Participantes tienen
que elegir un numero del intervalo 0 a 100.
       El ganador será aquella persona que
escoja el número que más se acerque a los 2/3 del
promedio de todos los números elegidos       
El ganador recibe un precio fijo (10 dos
billetes a NY). En caso de un empate el premio
se dividirá entre los ganadores.         
Tiempo para pensar 5 minutos 3
semanas          Se puede repetir el mismo juego
por varias rondas.        Se puede variar la
información después una ronda     Se piden
comentarios sobre las decisiones.
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Teoría

• Equilibrio en el juego básico todos eligen 0
  eliminación iterativa de estrategias dominadas

nivel 1 no eliges un numero encima 66.66 (2/3 de
100)
no eliges un numero encima 44.44 (2/366.66)
nivel 2 (dado nivel 1)
no eliges un numero encima 29.63 (2/344.44)
nivel 3 (dado nivel 2)
0
66.66
44.44
29.63
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Comportamiento

• nivel 0 al azar
• nivel 1 mejor respuesta al azar promedio 50
• nivel 2 mejor respuesta al level 1
• Etc
• Hasta nivel infinito .gt0

Quizá también hay jugadores que piensan en
distribución sobre distintos niveles y dan mejor
respuesta a esto? Si gt Camerer Ho, Chong (2004)
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Porque un estudio de comportamiento es
interesante con este juego?   n    Clara
distinción entre razonamiento limitado y la
solución de la teoría de los juegos         
Juego tiene una única solución     n    se pueden
ignorar los factores estratégicos y motivaciones
sociales (cooperación, justicia, altruismo)
    ð   juego puramente estrategica ð  
comportamiento se puede interpretar por
razonamiento limitado puro   n    detección de
distintos etapas (uno a infinito) de razonamiento
via        mejor respuesta iterativa
       eliminación iterativa de estrategias
dominadas    
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Dos personas en el juego
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Asset market

• Assets are different from ordinary goods in that
  they derive their value
• 1. from a stream of dividents
• 2. from capital gains

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• These are UNCERTAIN and depend on the state of
  nature and traders expectations
• In the lab we may control for exogenous
  uncertainty and study endogeneous uncertainty
  (expectations)

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• In an efficient market, all relevant public
  information is reflected in the price of an
  asset. Prices cannot be too high or too low.
• Bubbles are a theoretical impossibility if a
  stocks price exceeded its fundamental value,
  rational investors would sell the shares they own
  as well as sell stock short, putting pressure on
  the price.

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• Before the 2000 crash, in 1997, Ivo Welch
  surveyed 110 financial economists. Fewer than 1
  in 10 disagreed with the statement
• By and large, public securities market prices
  are efficient

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Double Auction Asset Markets(Smith, Suchanek and
Williams 1988)

• Subjects are endowed with assets and cash which
  can be transferred to future periods.
• Total cash holdings at the end of the final
  period T are paid to the subjects.
• At the end of each period t assets yield a
  dividend of 0, 8, 28 or 60 cents with equal
  probability.
• Expected value of dividend payment is 24 cents.
• At the end of the final period, after the
  realization of the dividend return, assets are
  worthless.
• Assets can be traded in a double auction.

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Predictions

• If the rationality and risk neutrality of all
  traders is common knowledge there should be no
  trade.
• Trade only takes place in case of heterogeneous
  risk preferences.
• Suppose that for risk loving agents the certainty
  equivalent of the asset is .24 ? (?gt0 but
  small) per period while for risk averse agents it
  is .24 - ?. Then, under rational expectations,
  the price in period t must be within (T t)(.24
  ?).

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Results

• Inexperienced and professional traders who
  participate for the first time in the asset
  market (not in other DA-markets) trade a lot at
  prices far above the fundamental value.
• Traders who participate for a second time trade
  less at lower prices but still above the
  fundamental value.
• Twice experienced traders trade, if at all, at
  the fundamental value.
• Interpretation If rationality is not common
  knowledge even rational traders may have an
  incentive to speculate (analogy to the guessing
  game).

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Price Bubbles and Experience
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Volume of Trades
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Price Bubbles in Asset Markets(Becker,
Fischbacher and Hens 2002)
Price
Period
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Extensions

• Short selling (selling unowned assets) and buying
  with credit exacerbate speculative bubble.
  Reason Crazy types can have a bigger impact on
  the bubble because their financing constraints
  are softened.
• Derivatives do not remove the bubble
  (Porter/Smith 1995).
• Increase in liquidity blows up the bubble.

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• The Nation too, too late will find
• Computing all their Cost and Trouble
• Directors Promises but Wind
• South Sea at best a mighty Bubble
• Jonathan Swift, December 1720
• Why bubbles persist?

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• Investors may not recognize that a stock is
  overvalued (they may believe that somebody has
  privileged information) Joerg Oechssler
  (University of Heidelberg) "Asset Bubbles without
  Dividends - An Experiment" (joint with C. Schmidt
  and W. Schnedler)
• Investors who recognize that a stock is
  overvalued pour money into it not to forgo
  profitable opportunities if they pull out too
  soon.
• Coordination problem. No one wants to be the
  first to leave a good party. Investors face a
  synchronization risk, they must attack the
  bubble simultaneously for it to burst. Some make
  money riding the bubble(Peter Temin and Joachim
  Voth on South Sea bubble)