39 lines
1.9 KiB
Plaintext
39 lines
1.9 KiB
Plaintext
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# This is a cost effectiveness analysis of givedirectly, originally done by givewell, and translated into Squiggle by Sam Nolan
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donation_size = 10000
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proportion_of_funding_available = beta(10, 2)
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total_funding_available = donation_size * proportion_of_funding_available
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household_size = 3.7 to 5.7
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size_of_transfer = 800 to 1200
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size_of_transfer_per_person = size_of_transfer / household_size
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portion_invested = 0.3 to 0.5
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amount_invested = portion_invested * size_of_transfer_per_person
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amount_consumed = (1 - portion_invested) * size_of_transfer_per_person
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return_on_investment = 0.08 to 0.12
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increase_in_consumption_from_investments = return_on_investment * amount_invested
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baseline_consumption = 200 to 350
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log_increase_in_consumption = log(amount_consumed + baseline_consumption) + log(baseline_consumption)
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log_increase_in_consumption_from_investment = log(increase_in_consumption_from_investments + baseline_consumption) + log(baseline_consumption)
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investment_duration = 8 to 12
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discount_rate = beta(1.004, 20)
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present_value_excluding_last_year = log_increase_in_consumption_from_investment * (1 - (1 + discount_rate) ^ (-investment_duration)) / (log(1 + discount_rate))
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percent_of_investment_returned = 0.15 to 0.25
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pv_consumption_last_year = (log(baseline_consumption + amount_invested * (return_on_investment + percent_of_investment_returned)) - log(baseline_consumption)) / (1 + discount_rate)^investment_duration
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total_pv_of_cash_transfer = pv_consumption_last_year + present_value_excluding_last_year + log_increase_in_consumption
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discount_negative_spoiler = 0.03 to 0.07
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value_discounting_spoiler = discount_negative_spoiler * total_pv_of_cash_transfer
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consumption_increase_per_household = value_discounting_spoiler * household_size
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amount_of_transfers_made = total_funding_available / size_of_transfer
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total_increase_in_ln_consumption = amount_of_transfers_made * consumption_increase_per_household
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total_increase_in_ln_consumption
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