def start_gamma2_imp(model, lval: str, rval: str):
    """
    Calculate starting value for parameter in data given data in model.

    For Imputer -- just copies values from original model.
    Parameters
    ----------
    model : Model
        Imputer instance.
    lval : str
        L-value name.
    rval : str
        R-value name.

    Returns
    -------
    float
        Starting value.

    """
    mx = model.mod.mx_gamma2
    rows, cols = model.mod.names_gamma2
    i, j = rows.index(lval), cols.index(rval)
    v = mx[i, j]
    return v