Climate clubs: An experimental study of Nordhaus' proposal to mitigate climate change

Dataset Description: Climate_Clubs_data.csv This dataset contains data from a laboratory experiment on cooperative behavior in the context of climate clubs and public goods games. It combines data from four experimental treatments (T1–T4) conducted as part of the “Climate Clubs” project. The dataset includes 2,700 observations and 27 variables, each corresponding to individual-level decisions and outcomes across multiple rounds of the experiment. Each observation represents one participant’s actions in one round within a specific experimental session and group. File Overview Filename: Climate_Clubs_data.csv Format: CSV (comma-separated values) Number of rows: 2,700 Number of columns: 27 Encoding: UTF-8 Variable Description Variable Description participant.id_in_session Numeric identifier for the participant within a session. participant.code Unique alphanumeric participant code assigned by oTree. participant._index_in_pages, participant._max_page_index, participant._current_app_name, participant._current_page_name Technical variables automatically generated by oTree for session management and page tracking. participant._round_number Current round number within the session. participant.time_started Timestamp indicating when the participant started the session. player.id_in_group Player’s position within the experimental group. player.automatic_decision Binary variable indicating whether the system made an automatic decision (1 = yes, 0 = no). player.pledge Participant’s initial pledge decision (if applicable in the treatment). player.commitment Participant’s commitment decision in the implementation phase (if applicable). player.endowment The player’s individual endowment in that round (measured in experimental currency units). player.contribution Amount contributed to the public good (in experimental currency units). player.my_total_payment Participant’s total cumulative earnings by the end of the session. player.payoff_ronda Participant’s payoff in the specific round. player.X, player.Y Coordinates or auxiliary variables used to record decisions or outcomes in the experimental interface. player.timeout_pledge, player.timeout_commit, player.timeout_contr Binary indicators of whether the participant timed out (1 = timeout, 0 = response given) during each decision stage. group.id_in_subsession Numeric identifier for the group within the session. group.coalition_flag Indicates whether a coalition was formed in the group during that round (1 = coalition formed, 0 = not formed). subsession.round_number Round number within the experimental subsession. session.code Unique session identifier assigned by oTree. group Alphanumeric group identifier (e.g., “1A”, “2B”). treatment Experimental treatment condition (T1–T4). Notes Treatments T1–T4 correspond to different experimental conditions related to decision-making in public goods games (e.g., with or without unanimity, with or without sanction mechanisms). Missing values (NA) occur where variables are not applicable to certain treatments or decision stages. Time variables are in UTC. All identifiers (participants, sessions) are anonymized and non-identifiable.