Lobsters 2016. According to the Maine Department of Marine Resources, in 2016 more than 130,800,000 pounds of lobster were landed in Maine—a catch worth more than $533.09M. The lobster fishing industry is carefully controlled and licensed, and facts about it have been recorded for more than a century, so it is an important industry that we can examine in detail. We’ll look at annual data (available at www.maine.gov/dmr) from 1950 through 2016.

The value of the annual lobster catch has grown.

Here’s a scatterplot of the value in millions of dollars over time:

a) Which regression assumptions and conditions appear to be violated according to this plot?

Here’s a scatterplot of the log of the value:

b) Discuss the same assumptions as in part

a. Does taking logs make these data suitable for regression?
After performing a regression on the log values, we obtain the following plot of residuals:

c) Discuss what this plot shows. Would a different transformation be likely to do better than the log? Explain.

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Value ($M) 500 375 250 125 + + + + 1950 1965 1980 1995 2010 Year