Explaining 1 line of codes

[wesso dadoyan]

Hi,

I have advanced stata codes that i am trying to build on in order to generate results. However, since I am a beginner in stata, I wasn't able to interpret the line in order to change the variables according to my needs. I would be very very grateful if someone explains this line to me (and please bear my ignorance):

model_dy reg L(0/`lag').dl_`cat'_rloans L(1/`lag').epu_`epu' L(1/`lag').dy L(1/`lag').dr L(1/`lag').RegQ L(1/`lag').credit_controls L(1/`lag').cexp i.quarter

The variables that I have in the dataset are :

name

q_date

dl_tot_rloans

dl_cai_rloans

dl_rea_rloans

dl_con_rloans

dr

dy

credit_controls

RegQ

epu_hist_new

epu_finc

epu_headline

cexp

quarter

jgdp

So mainly I don't undertstand the following:
1.L(0/`lag') and L(0/`lag')
2.the dot represents what ? for example in L(1/`lag').epu. is this the one period lagged value of epu? if this is the case then i.quarter is what ?
3.L(0/`lag').dl_`cat' is what? (I don't have any cat variable)
4. Finally,in L(1/`lag').epu_`epu' why is there two consecutive epu? (in other words what i the job of _`epu')?

Many thanks

[Phil Bromiley]

OK, first you're more likely to get a helpful response if you follow the FAQ on asking questions - Stata code in code delimiters, Stata output, and sample data using dataex. Also simplify things as far as possible while still replicating your problem.

First, you need to read the documentation on macros and lags. You clearly don't understand them.

Try running this with "set trace on". This will tell you how Stata is interpreting your code (and particularly your macros). You might also list your macros (macro list) to see what has been created. I don't know what model_dy means.
Anything `x' with those marks on either side is a local macro. So `x' refers to a local macro x. That just holds whatever text or number has been placed in that macro. It doesn't refer to a variable per se (although it might hold the name of a variable you want to use).
1. L(1/2).x means you include one and two lags of x.
2. the dot connects a lag operator to the variable it operates on
3. `cat' refers to a local macro called cat. In this context it means you have a variable dl_`cat' that starts dl_ and ends with whatever is in `cat'.
4. Likewise, epu_`epu' refers to a variable called epu_ followed by whatever is in the local macro epu.