Industrial Organization and Experimental Economics Huanren(Warren) Zhang

Why lab experiments?  Test theoretical prediction in controlled experiments  In the field all kinds of factors intertwined together, hard to pin down determinative factors  When without theories, observed regularities in lab experiments can help discover new theories

Two Papers to be Presented  I. Firm Behavior Transparency in Markets for Experience Goods (Bastian Henze and Florian Schuett)  II. Consumer Behavior Understanding Consumers' Choice of Pricing Schemes (Natalia Shestakova)

I. Transparency: Motivating Example  European lawmakers mandate disclosure of information on Internet Service Providers’ network management (increase transparency for an experience good)  Theory predicts firms will voluntarily disclose the information because producer surplus is higher when quality is observable.

Firm Behavior: Relevant Literature  (Shaked and Sutton, 1982): When quality is observable, firms are predicted to engage in vertical differentiation in order to relax price competition.  (Akerlof, 1970): When consumers cannot observe quality, firms will supply inefficiently low quality

So the authors want to…  Investigate the role of transparency in the market for an experience good using a lab experiment To do that, they  Vary the degree to which consumers are informed about quality (four different treatments) and compare the results

Model:

Model

Four Treatments

Parameters

Theoretical Prediction: Full Information

Theoretical Prediction: No information  Perfect Bayesian equilibrium (PBE): 1. players’ strategies must be optimal given beliefs 2. beliefs must be derived from equilibrium strategies using Bayes’ rule whenever possible.

Theoretical Prediction: No information

 No theory has addressed whether there can be a signaling equilibrium when firms choose from a set of more than two possible levels of quality.  But it is unlikely that separation would remain an equilibrium when there are more than two levels of quality.

Theoretical Prediction: Subset  The literature has not analyzed the case of multiple quality levels.  The presence of informed consumers makes the existence of a separating equilibrium, where prices signal qualities, more likely.  The informed consumers exert a positive informational externality on uninformed consumers: creating a cost of mimicking high-quality firms.

Theoretical Prediction: Imperfect Signal  No theories exist dealing with the case of imperfect information about quality.  Intuitively we would expect a similar argument as in the subset treatment to apply, and the theoretical predictions for both treatments would be similar.

Experimental Design  30 periods followed 2 practice periods  Subjects randomly assigned to be either a seller or a buyers, and the roles remain the same for the entire experiment  Each session has three groups of sellers and three groups of buyers.  With probability of 1/3, sellers are rematched with buyers in each period.

Experimental Design  Fully informed buyers (full-info and subset treatments) were played by the computer.  full-info: 4 sessions, 6 subjects each (12 automated buyers)  subset: 5 sessions, 12 subjects each (6 automated buyers)  no-info : 3 sessions, 18 subjects each  signal: 4 sessions, 18 subjects each

Results

Table 5: p-values for one-sided rank sum tests of differences in quality supplied (final 15 periods)

Conclusion: Transparency  Firms do not differentiate quality under full information.  Under no information, quality is low. At the same time, firms manage to maintain prices substantially above marginal cost*.  In the subset and signal treatments, quality is significantly above the no-information level  Consumer’s surplus increases with the increase of quality transparency

II. Consumer Choice: Motivating Example  Suppose you consume 80 minutes/month, which plan will you choose?

Consumer Choice: Background  Traditional economics assumes people are rational (like a powerful calculating machine)  Experimental economics of individual behavior is closely related to behavioral economics  Behavioral economics claims that people’s rationality is bounded  Instead of calculating the optimal solution, people use heuristics (rules of thumb) to find a satisfactory solution

The Model

The Model: Illustration

“Expected Demand” Heuristic (EDH)

EDH: Illustration

“Match” Heuristic (MH)  Prediction MH: if consumers can construct a match between their demand and one of pricing schemes, they choose such scheme unless it is “obviously worse”(the fixed fee of the matched scheme is higher than the fixed fee of a scheme with a larger number of included units) than one of the remaining schemes.

MH: Illustration

Experimental Design

Results

 Result 1: n the 27 main experimental tasks, only 55.6% of choices are first-best.  Result 2: Expected demand heuristic is the best in predicting subjects’ choices.  Match heuristic gives reasonable prediction.

Conclusion: Consumer Choice  The “irrationalities” observed in experiments on individual decision-making gives rise to behavioral economics  People use heuristics to speed up the decision-making process, but this sometimes gives suboptimal solution

Final Comments  Experiments can test the predictive power of a theory in a controlled environment  When no relevant theories are available, experiments can give valuable empirical implication  Empirical regularities observed in lab experiments can help improve current theories or develop new theories