File size: 7,090 Bytes
6ecdfc7
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
import numpy as np
import pandas as pd
import pytest

from casuallab.interference import (
    ExposureMappingConfig,
    TwoStageSaturationConfig,
    add_mapped_exposures,
    estimate_exposure_response,
    two_stage_saturation_assignment,
)


def _units(n_zones: int = 12, n_periods: int = 8) -> pd.DataFrame:
    return pd.MultiIndex.from_product(
        [range(n_periods), range(n_zones)],
        names=["period_id", "zone_id"],
    ).to_frame(index=False)


def _ring_edges(n_zones: int) -> pd.DataFrame:
    return pd.DataFrame(
        {
            "focal_zone_id": np.arange(n_zones),
            "neighbor_zone_id": np.roll(np.arange(n_zones), -1),
            "weight": 1.0,
        }
    )


def test_two_stage_saturation_is_deterministic_balanced_and_records_probabilities() -> None:
    config = TwoStageSaturationConfig(
        n_clusters=6,
        individuals_per_cell=40,
        saturation_levels=(0.0, 0.5, 1.0),
        seed=91,
    )
    first = two_stage_saturation_assignment(_units(), config)
    second = two_stage_saturation_assignment(_units(), config)
    pd.testing.assert_frame_equal(first, second)

    cluster_arms = first.groupby("cluster_id")["cluster_saturation"].nunique()
    assert cluster_arms.eq(1).all()
    assert (
        first[["cluster_id", "cluster_saturation"]]
        .drop_duplicates()["cluster_saturation"]
        .value_counts()
        .sort_index()
        .to_dict()
        == {0.0: 2, 0.5: 2, 1.0: 2}
    )
    assert set(first["saturation_assignment_probability"]) == {1 / 3}
    assert first.loc[first["cluster_saturation"] == 0, "treated_units"].eq(0).all()
    assert first.loc[first["cluster_saturation"] == 1, "treated_units"].eq(40).all()
    assert first["assigned_treatment"].between(0, 1).all()
    assert first["randomization_cluster"].nunique() == 6
    assert set(first["evidence_type"]) == {"randomized_design_assignment"}


def test_two_stage_saturation_config_rejects_unsupported_arm_geometry() -> None:
    with pytest.raises(ValueError, match="number of saturation levels"):
        TwoStageSaturationConfig(n_clusters=2, saturation_levels=(0.0, 0.5, 1.0))
    with pytest.raises(ValueError, match="sum to one"):
        TwoStageSaturationConfig(
            n_clusters=4,
            saturation_levels=(0.0, 1.0),
            saturation_probabilities=(0.2, 0.2),
        )


def test_mapped_exposure_uses_predeclared_neighbors_and_exact_time_lags() -> None:
    assignments = _units(n_zones=4, n_periods=4)
    assignments["treatment"] = (
        assignments["zone_id"] + assignments["period_id"]
    ) % 2
    mapped = add_mapped_exposures(
        assignments,
        _ring_edges(4),
        history_lags=1,
    )

    lookup = assignments.set_index(["zone_id", "period_id"])["treatment"]
    for row in mapped.itertuples(index=False):
        expected_neighbor = lookup.loc[((row.zone_id + 1) % 4, row.period_id)]
        assert row.neighbor_exposure == expected_neighbor
        if row.period_id == 0:
            assert np.isnan(row.history_exposure)
            assert row.history_support == 0
        else:
            assert row.history_exposure == lookup.loc[(row.zone_id, row.period_id - 1)]
            assert row.history_support == 1
    assert mapped["exposure_mapping_id"].nunique() == 1


def test_unmapped_focal_zone_remains_unknown_not_zero() -> None:
    assignments = _units(n_zones=3, n_periods=2)
    assignments["treatment"] = 0.0
    edges = pd.DataFrame(
        {
            "focal_zone_id": [0, 1],
            "neighbor_zone_id": [1, 2],
            "weight": [1.0, 1.0],
        }
    )
    mapped = add_mapped_exposures(assignments, edges)
    assert mapped.loc[mapped["zone_id"] == 2, "neighbor_exposure"].isna().all()
    assert mapped.loc[mapped["zone_id"].isin([0, 1]), "neighbor_exposure"].eq(0).all()


def test_exposure_mapped_regression_recovers_own_neighbor_and_history_slopes() -> None:
    assignment = two_stage_saturation_assignment(
        _units(n_zones=12, n_periods=40),
        TwoStageSaturationConfig(
            n_clusters=12,
            individuals_per_cell=80,
            saturation_levels=(0.0, 0.35, 0.7, 1.0),
            seed=81,
        ),
    )
    mapped = add_mapped_exposures(assignment, _ring_edges(12), history_lags=1)
    mapped["baseline"] = np.sin(mapped["zone_id"])
    rng = np.random.default_rng(719)
    mapped["outcome"] = (
        4.0
        + 2.0 * mapped["treatment"]
        + 1.5 * mapped["neighbor_exposure"]
        + 0.7 * mapped["history_exposure"]
        + 0.25 * mapped["baseline"]
        + rng.normal(0.0, 0.03, len(mapped))
    )
    result = estimate_exposure_response(
        mapped,
        ExposureMappingConfig(covariates=("baseline",)),
    ).set_index("exposure_term")

    assert result.loc["treatment", "estimate"] == pytest.approx(2.0, abs=0.05)
    assert result.loc["neighbor_exposure", "estimate"] == pytest.approx(1.5, abs=0.05)
    assert result.loc["history_exposure", "estimate"] == pytest.approx(0.7, abs=0.05)
    assert result["inference_valid"].all()
    assert set(result["target_estimand"]) == {
        "controlled_zone_direct_effect",
        "spillover_effect",
        "controlled_history_exposure_response",
    }
    assert result["effect_scale"].str.contains("not the full-policy").all()


def test_exposure_estimator_rejects_collinear_own_and_neighbor_exposure() -> None:
    frame = _units(n_zones=4, n_periods=4)
    frame["treatment"] = np.tile([0.0, 1.0, 0.0, 1.0], 4)
    frame["neighbor_exposure"] = frame["treatment"]
    frame["outcome"] = frame["treatment"]
    frame["randomization_cluster"] = "z_" + frame["zone_id"].astype(str)
    with pytest.raises(ValueError, match="rank deficient"):
        estimate_exposure_response(
            frame,
            ExposureMappingConfig(history_exposure=None),
        )


def test_exposure_estimator_fails_closed_when_configured_history_is_missing() -> None:
    frame = _units(n_zones=4, n_periods=4)
    frame["treatment"] = np.tile([0.0, 1.0, 0.0, 1.0], 4)
    frame["neighbor_exposure"] = np.tile([1.0, 0.0, 1.0, 0.0], 4)
    frame["outcome"] = frame["treatment"]
    frame["randomization_cluster"] = "z_" + frame["zone_id"].astype(str)

    with pytest.raises(ValueError, match="missing configured history column"):
        estimate_exposure_response(frame)


def test_exposure_estimator_rejects_mixed_mapping_versions() -> None:
    assignment = two_stage_saturation_assignment(
        _units(n_zones=8, n_periods=10),
        TwoStageSaturationConfig(
            n_clusters=8,
            individuals_per_cell=20,
            saturation_levels=(0.0, 0.5, 1.0),
            seed=18,
        ),
    )
    frame = add_mapped_exposures(assignment, _ring_edges(8), history_lags=1)
    frame["outcome"] = (
        2.0 * frame["treatment"]
        + frame["neighbor_exposure"]
        + 0.5 * frame["history_exposure"]
    )
    frame.loc[frame["period_id"] >= 5, "exposure_mapping_id"] = "second-map"

    with pytest.raises(ValueError, match="one predeclared exposure mapping"):
        estimate_exposure_response(frame)