Robert Porter

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The optimal features with which to discriminate between regions and, thus, segment an image often differ depending on the nature of the image. Many real images are made up of both smooth and textured regions and are best segmented using different features in different areas. A scheme that automatically selects the optimal features for each pixel using(More)
  • Thomas N Hubbard, Tim Bresnahan, Judy Chevalier, Andrew Dick, Kevin Murdock, Randy Kroszner +9 others
  • 2001
Moral hazard exists in expert service markets because sellers have an incentive to shade their reports of buyers' condition to increase the short-run demand for their services. The California vehicle emission inspection market offers a rare opportunity to examine how reputational incentives work in such a market. I show that consumers are 30% more likely to(More)
  • Allan Collard-Wexler, Robert Porter, Michael Whinston, Aviv Nevo, Shane Greeenstein I, Lynn Riggs +4 others
  • 2009
This paper presents a quantitative model of productivity dispersion to explain why inefficient producers are slowly selected out of the ready-mix concrete industry. Measured productivity dispersion between the 10th and 90th percentile falls from a 4 to 1 difference using OLS, to a 2 to 1 difference using a control function. Due to volatile productivity and(More)
  • Research Showcase, Cmu, Lee G Branstetter, Mariko Sakakibara, Lee Branstetter, Wesley Cohen +9 others
  • 2015
Does an expansion of patent scope induce more innovative effort by firms? We examine responses to the Japanese patent reforms of 1988. Interviews with practitioners and professional documents for patent agents suggest the reforms significantly expanded the scope of patent rights. However, econometric analysis using both Japanese and U.S. patent data on 307(More)
  • V Joseph Hotz, Mo Xiao, Dan Ackerberg, Alberto Bernardo, Hongbin Cai, Harold Demsetz +8 others
  • 2010
We examine the incentives for firms to voluntarily disclose otherwise private information about the quality attributes of their products. In particular, we focus on the case of differentiated products with multiple attributes and heterogeneous consumers. We show that there exist certain configurations of consumers' multi-dimensional preferences under which(More)
Review panels determine the success or failure of most proposals, and grant writers are well advised to polish their prose in a manner that will win their approval. Indeed, many successful grant writers count their service on review panels among the most powerful learning experiences in their own research careers. There is abundant information on how review(More)
  • V Joseph, Hotz Ucla, Mo Xiao Ucla, Dan Ackerberg, Harold Demsetz, Ginger Zhe +7 others
  • 2002
In this paper, we examine the incentives for firms to voluntarily disclose otherwise private information about quality attributes of differentiated products when those products have multiple attributes and consumers are heterogeneous in their tastes over these attributes. In particular , we focus on whether the so-called " unraveling result " —in(More)