Combining Macros and Loops (Loops)

Here you’ll combine local macros and foreach loops along with varlist to create new variables and run multiple regressions.

1. Create a local macro named logvars that contains three nonnegative variables that you expect to be skewed:
   • yield_kg
   • harvest_value_USD
   • totcons_USD

Use a foreach loop over the variables in logvars to create log-transformed versions of each variable:

• For each variable v in logvars, generate ln_v’ = ln(v')
• Label each new variable "log of v"
• Use sum to calculate the mean for each logged variable

What is the mean value of each variable?

1. Now define two more local macros:
   • local yvars ln_*
   • local controls plot_area_GPS irrigated nitrogen_kg female_manager

Use a foreach loop to run regressions of each outcome in yvars on the same set of controls. In each regression, what controls are not significant?

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