Building on Spence's (1973) seminal work, discuss the theoretical predictions that Haan et al. (2011 ) challenges and how they use experimental techniques to test these new hypotheses empirically in the lab. What are noisy signals and how do they impact behavior? Identify any particular constraints to identifying externally valid experimental results. Discuss the co-existence of separating and pooling equilibria in Haan et al.'s (2011) analysis, highlighting any necessary and/or sufficient conditions to maintain these as equilibria. Note: Write about 2 paragraphs, explaining the findings overall.