# This is a cost effectiveness analysis of givedirectly, originally done by givewell, and translated into Squiggle by Sam Nolan
donation_size = 10000
proportion_of_funding_available = beta(10, 2)
total_funding_available = donation_size * proportion_of_funding_available
household_size = 3.7 to 5.7
size_of_transfer = 800 to 1200
size_of_transfer_per_person = size_of_transfer / household_size

portion_invested = 0.3 to 0.5
amount_invested = portion_invested * size_of_transfer_per_person
amount_consumed = (1 - portion_invested) * size_of_transfer_per_person
return_on_investment = 0.08 to 0.12
increase_in_consumption_from_investments = return_on_investment * amount_invested
baseline_consumption = 200 to 350
log_increase_in_consumption = log(amount_consumed + baseline_consumption) + log(baseline_consumption)
log_increase_in_consumption_from_investment = log(increase_in_consumption_from_investments + baseline_consumption) + log(baseline_consumption)
investment_duration = 8 to 12
discount_rate = beta(1.004, 20)

present_value_excluding_last_year = log_increase_in_consumption_from_investment * (1 - (1 + discount_rate) ^ (-investment_duration)) / (log(1 + discount_rate))

percent_of_investment_returned = 0.15 to 0.25

pv_consumption_last_year = (log(baseline_consumption + amount_invested * (return_on_investment + percent_of_investment_returned)) - log(baseline_consumption)) / (1 + discount_rate)^investment_duration

total_pv_of_cash_transfer = pv_consumption_last_year + present_value_excluding_last_year + log_increase_in_consumption

discount_negative_spoiler = 0.03 to 0.07

value_discounting_spoiler = discount_negative_spoiler * total_pv_of_cash_transfer

consumption_increase_per_household = value_discounting_spoiler * household_size

amount_of_transfers_made = total_funding_available / size_of_transfer

total_increase_in_ln_consumption = amount_of_transfers_made * consumption_increase_per_household

total_increase_in_ln_consumption