Don't bother with the book or lecture, just do the "Test your understanding" exercises she puts out, and you'll get an "A."
Yes, it's a difficult class. That being said, with hard work (and horrible math skills to begin with) I managed to pull an A- in the class. 3 "quizzes" compile your entire grade, your 2 highest scores make up 90% and the lowest for 10%, so even if you fail one of the quizzes you can still do well. STUDY ALL PRACTICE PROBLEMS SHE ASSIGNS TO DO WELL!
One of the worst Econ profs I've had at UCSB. And that's saying something. You're better off skipping class and teaching yourself.
Even though some of these comments are true, I did not think Mehra was that bad. While she makes mistakes, she is one of the few Econ profs who goes into detailed explanations of the mathematical procedures. Her test were hard but very fair. I was never shocked by what I saw, but the problems themselves can be very long and complicated.
Horrible class ever. She and her TA kept making so many mistakes and confused us, even Econ is confusing already. the quizzes were from out of nowhere. But you have to take it to complete your major. Luck is all you need for this horrible class.
The class itself is not hard. Both lecture and section are a complete waste of time, so don't bother going. Best way to get an A is to study all the practice questions, homework (not mandatory), and practice exams she gives out prior to each test. Do them each several times. The solution manual is on reserve. Allow yourself 48 hours to cram.