def behavioral_assumptions(tb):
    """
    Return list of behavioral assumptions used

    Parameters
    ----------
    tb: TaxBrain object
        instance of TaxBrain object for analysis

    Returns
    -------
    assumptions: list
        list of behavioral assumptions used
    """
    behavior_map = {
        "sub": "Substitution elasticity of taxable income: {}",
        "inc": "Income elasticity of taxable income: {}",
        "cg": "Semi-elasticity of long-term capital gains: {}"
    }
    assumptions = []
    # if there are some behavioral assumptions, loop through them
    if tb.params["behavior"]:
        for param, val in tb.params["behavior"].items():
            assumptions.append(
                behavior_map[param].format(val)
            )
    else:
        assumptions.append("No behavioral assumptions")
    return assumptions