from otree.api import * doc = """ In Cournot competition, firms simultaneously decide the units of products to manufacture. The unit selling price depends on the total units produced. In this implementation, there are 2 firms competing for 1 period. """ class C(BaseConstants): NAME_IN_URL = 'cournot' PLAYERS_PER_GROUP = 2 NUM_ROUNDS = 1 # Total production capacity of all players TOTAL_CAPACITY = 60 MAX_UNITS_PER_PLAYER = int(TOTAL_CAPACITY / PLAYERS_PER_GROUP) class Subsession(BaseSubsession): pass class Group(BaseGroup): unit_price = models.CurrencyField() total_units = models.IntegerField(doc="""Total units produced by all players""") class Player(BasePlayer): units = models.IntegerField( min=0, max=C.MAX_UNITS_PER_PLAYER, doc="""Quantity of units to produce""", label="How many units will you produce (from 0 to 30)?", ) # FUNCTIONS def set_payoffs(group: Group): players = group.get_players() group.total_units = sum([p.units for p in players]) group.unit_price = C.TOTAL_CAPACITY - group.total_units for p in players: p.payoff = group.unit_price * p.units def other_player(player: Player): return player.get_others_in_group()[0] # PAGES class Introduction(Page): pass class Decide(Page): form_model = 'player' form_fields = ['units'] class ResultsWaitPage(WaitPage): body_text = "Waiting for the other participant to decide." after_all_players_arrive = set_payoffs class Results(Page): @staticmethod def vars_for_template(player: Player): return dict(other_player_units=other_player(player).units) page_sequence = [Introduction, Decide, ResultsWaitPage, Results]