Mingliang Li and Justin Tobias, "Calculus Attainment and Grades Received in
Intermediate Economic Theory", Journal of Applied Econometrics, Vol. 21,
No. 6, 2006, pp. 893-896.

The data set used in this paper is the same as the original data set
utilized in 

  J. S. Butler, T. Aldrich Finegan, and John J. Siegfried, "Does More Calculus
  Improve Student Learning in Intermediate Micro and Macro Economic Theory",
  Journal of Applied Econometrics, Vol. 13, No. 2, 1998, pp. 185-202. 

The URL for this original data set is

  http://www.econ.queensu.ca/jae/1998-v13.2/butler-finegan-siegfried/

The format of the data has been changed, however. The data employed in this
paper are stored in the ASCII file jae-4963-data.txt, which is zipped in the
file ltdata.zip. The file jae-4963-data.txt is in DOS format, and it size is
459,186 bytes.

The file is rectangular with 609 lines. Each line corresponds to an
observation. For each observation, 47 variables are available. Variables are
separated from each other with white spaces. They are enumerated as follows:

(1) Constant
(2) Id number of 609 students
(3) Highest level of math attained, 0-6 corresponding to Math 170, 171a, 172a,
    171b, 172b, 221a, 221b or 222
(4) SAT Math score (divided by 100)
(5) Foreign language proficiency dummy
(6) Sex dummy (female = 1, male = 0)
(7) Expected major is economics
(8) Expected major is other social science
(9) Expected major is natural science
(10) Expected major is humanities
(11) Years of HS Advanced Math is at least one but less than two
(12) Years of HS Advanced Math is two
(13) Years of HS Advanced Math is more than two
(14) Years of HS physics is at least one but less than two
(15) Years of HS physics is at least two
(16) Years of HS chemistry is at least one but less than two
(17) Years of HS chemistry is at least two
(18) Observation number, 1-609
(19) Grade in Econ 231
(20) The selection correction term calculated in the original paper of
     Butler et al.
(21) Econ 231 taken in Sophomore year
(22) Econ 231 taken in Senior year
(23) MICRO-1 and MICRO-2 in the same academic year
(24) At least one semester between MICRO-1 and MICRO-2
(25) Math 171a is highest completed math
(26) Math 172a is highest completed math
(27) Math 171b is highest completed math
(28) Math 172b is highest completed math
(29) Math 221a is highest completed math
(30) Math 221b or 222 is highest completed math
(31) Grade in Math 170  if it is the highest completed math
(32) Grade in Math 171a if it is the highest completed math
(33) Grade in Math 172a if it is the highest completed math
(34) Grade in Math 171b if it is the highest completed math
(35) Grade in Math 172b if it is the highest completed math
(36) Grade in Math 221a if it is the highest completed math
(37) Grade in Math 221b or 222 if it is the highest completed math
(38) Grade in MACRO-1
(39) Instructor's grade deflator in MACRO-1
(40) Grade in MICRO-1
(41) Grade deflator of instructor in intermediate theory course
(42) Instructor's grade deflator in MICRO-1
(43) Class size of intermediate theory course
(44) Freshman Grade Point Average
(45) SAT Verbal score (divided by 100)
(46) Teacher of 231 (numerical code)
(47) Section of 231 (numerical code)