Blocked random assignment

assign_blocks.ado

program assign_blocks
    version 13.1
    syntax [varlist], totaln(integer) blocksize(integer)
    drop _all
    set obs `totaln'
    generate treatment_assigned = 1
    generate dice_roll = runiform()
    generate block = 1
    local half_block = `blocksize' / 2
    local n_blocks = `totaln' / `blocksize'
    forvalues block_number = 1/`n_blocks' {
        local blockstart = ((`block_number' - 1) * `blocksize') + 1
        local blockend = ((`block_number' - 1) * `blocksize') + `blocksize'
        replace block = `block_number' in `blockstart'/`blockend'
        create_block, na(`half_block') nb(`half_block') startindex(`blockstart') endindex(`blockend')
    }
end
* final line

create_block.ado

program create_block
    version 13.1
    syntax [varlist], na(integer) nb(integer) startindex(integer) endindex(integer)
    local total_N = `na' + `nb'
    local n1 = 0
    local n2 = 0
    forvalues row_number = `startindex'/`endindex' {
        local p1 = (`na' - `n1') / (`na' + `nb' - `n1' - `n2')
        local current_roll = dice_roll in `row_number'
        local is_two = `p1' < dice_roll in `row_number'
        replace treatment_assigned = 2 if `is_two' in `row_number'
        count if treatment_assigned == 1 in `startindex'/`row_number'
        local n1 = r(N)
        count if treatment_assigned == 2 in `startindex'/`row_number'
        local n2 = r(N)
    }
end
* Final line must contain newline