diff --git a/openfisca_core/config.py b/openfisca_core/config.py
new file mode 100644
index 000000000..c2e4e6ebb
--- /dev/null
+++ b/openfisca_core/config.py
@@ -0,0 +1,68 @@
+from __future__ import annotations
+
+from typing import Final, final
+
+import dataclasses
+import datetime
+
+from openfisca_core import indexed_enums as enum
+
+from . import types as t
+
+
+@final
+@dataclasses.dataclass(frozen=True)
+class ValueType:
+    dtype: t.DTypeLike
+    default: object
+    json_type: str
+    formatted_value_type: str
+    is_period_size_independent: bool
+
+
+value_types: Final = {
+    bool: ValueType(
+        dtype=t.DTypeBool,
+        default=False,
+        json_type="boolean",
+        formatted_value_type="Boolean",
+        is_period_size_independent=True,
+    ),
+    int: ValueType(
+        dtype=t.DTypeInt,
+        default=0,
+        json_type="integer",
+        formatted_value_type="Int",
+        is_period_size_independent=False,
+    ),
+    float: ValueType(
+        dtype=t.DTypeFloat,
+        default=0,
+        json_type="number",
+        formatted_value_type="Float",
+        is_period_size_independent=False,
+    ),
+    str: ValueType(
+        dtype=t.DTypeStr,
+        default="",
+        json_type="string",
+        formatted_value_type="String",
+        is_period_size_independent=True,
+    ),
+    enum.Enum: ValueType(
+        dtype=t.DTypeEnum,
+        default=None,
+        json_type="string",
+        formatted_value_type="String",
+        is_period_size_independent=True,
+    ),
+    datetime.date: ValueType(
+        dtype="datetime64[D]",
+        default=None,
+        json_type="string",
+        formatted_value_type="Date",
+        is_period_size_independent=True,
+    ),
+}
+
+__all__ = ["value_types"]
diff --git a/openfisca_core/entities/types.py b/openfisca_core/entities/types.py
index ef6af9024..2f05954ed 100644
--- a/openfisca_core/entities/types.py
+++ b/openfisca_core/entities/types.py
@@ -33,7 +33,6 @@ class RoleParams(TypedDict, total=False):
     "GroupEntity",
     "Role",
     "RoleKey",
-    "RoleParams",
     "RolePlural",
     "SingleEntity",
     "TaxBenefitSystem",
diff --git a/openfisca_core/indexed_enums/enum.py b/openfisca_core/indexed_enums/enum.py
index 960c16b91..fe67f4f31 100644
--- a/openfisca_core/indexed_enums/enum.py
+++ b/openfisca_core/indexed_enums/enum.py
@@ -29,10 +29,7 @@ def __init__(self, name: str) -> None:
     def encode(
         cls,
         array: (
-            EnumArray
-            | t.Array[numpy.str_]
-            | t.Array[numpy.int16]
-            | t.Array[numpy.int32]
+            EnumArray | t.Array[t.DTypeEnum] | t.Array[t.DTypeInt] | t.Array[t.DTypeStr]
         ),
     ) -> EnumArray:
         """Encode a string numpy array, an enum item numpy array, or an int numpy
@@ -68,7 +65,7 @@ def encode(
             array = numpy.select(
                 [array == item.name for item in cls],
                 [item.index for item in cls],
-            ).astype(numpy.int16)
+            ).astype(t.DTypeEnum)
 
         # Enum items arrays
         elif array.dtype.kind == "O":
@@ -92,9 +89,9 @@ def encode(
             array = numpy.select(
                 [array == item for item in klass],
                 [item.index for item in klass],
-            ).astype(numpy.int16)
+            ).astype(t.DTypeEnum)
 
-        array = numpy.asarray(array, dtype=numpy.int16)
+        array = numpy.asarray(array, dtype=t.DTypeEnum)
         return EnumArray(array, cls)
 
 
diff --git a/openfisca_core/indexed_enums/enum_array.py b/openfisca_core/indexed_enums/enum_array.py
index d8530f8d1..ce74ddae2 100644
--- a/openfisca_core/indexed_enums/enum_array.py
+++ b/openfisca_core/indexed_enums/enum_array.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from typing import NoReturn, overload
-from typing_extensions import TypeGuard
+from typing_extensions import Self, TypeGuard
 
 import numpy
 
@@ -25,35 +25,35 @@ def __new__(
         cls,
         input_array: t.Array[numpy.int16],
         possible_values: None | type[t.Enum] = None,
-    ) -> EnumArray:
+    ) -> Self:
         obj = numpy.asarray(input_array).view(cls)
         obj.possible_values = possible_values
         return obj
 
     # See previous comment
     def __array_finalize__(
-        self, obj: None | t.EnumArray | t.Array[numpy.generic]
+        self, obj: None | t.EnumArray | t.Array[t.DTypeObject]
     ) -> None:
         if obj is None:
-            return None
+            return
         if isinstance(obj, EnumArray):
             self.possible_values = obj.possible_values
-        return None
+        return
 
     @overload  # type: ignore[override]
-    def __eq__(self, other: None | t.Enum | type[t.Enum]) -> t.Array[numpy.bool_]: ...
+    def __eq__(self, other: None | t.Enum | type[t.Enum]) -> t.Array[t.DTypeBool]: ...
 
     @overload
-    def __eq__(self, other: object) -> t.Array[numpy.bool_] | bool: ...
+    def __eq__(self, other: object) -> t.Array[t.DTypeBool] | bool: ...
 
-    def __eq__(self, other: object) -> t.Array[numpy.bool_] | bool:
-        boolean_array: t.Array[numpy.bool_]
+    def __eq__(self, other: object) -> t.Array[t.DTypeBool] | bool:
+        boolean_array: t.Array[t.DTypeBool]
         boolean: bool
 
         if self.possible_values is None:
             return NotImplemented
 
-        view: t.Array[numpy.int16] = self.view(numpy.ndarray)
+        view: t.Array[t.DTypeEnum] = self.view(numpy.ndarray)
 
         if other is None or self._is_an_enum_type(other):
             boolean_array = view == other
@@ -71,12 +71,12 @@ def __eq__(self, other: object) -> t.Array[numpy.bool_] | bool:
         return boolean
 
     @overload  # type: ignore[override]
-    def __ne__(self, other: None | t.Enum | type[t.Enum]) -> t.Array[numpy.bool_]: ...
+    def __ne__(self, other: None | t.Enum | type[t.Enum]) -> t.Array[t.DTypeBool]: ...
 
     @overload
-    def __ne__(self, other: object) -> t.Array[numpy.bool_] | bool: ...
+    def __ne__(self, other: object) -> t.Array[t.DTypeBool] | bool: ...
 
-    def __ne__(self, other: object) -> t.Array[numpy.bool_] | bool:
+    def __ne__(self, other: object) -> t.Array[t.DTypeBool] | bool:
         return numpy.logical_not(self == other)
 
     def _forbidden_operation(self, other: object) -> NoReturn:
@@ -97,7 +97,7 @@ def _forbidden_operation(self, other: object) -> NoReturn:
     __and__ = _forbidden_operation  # type: ignore[assignment]
     __or__ = _forbidden_operation  # type: ignore[assignment]
 
-    def decode(self) -> t.Array[numpy.int16]:
+    def decode(self) -> t.Array[t.DTypeEnum]:
         """Return the array of enum items corresponding to self.
 
         For instance:
@@ -116,10 +116,10 @@ def decode(self) -> t.Array[numpy.int16]:
 
         return numpy.select(
             [self == item.index for item in self.possible_values],
-            [item for item in self.possible_values],  # type: ignore[misc]
+            list(self.possible_values),  # pyright: ignore[reportArgumentType]
         )
 
-    def decode_to_str(self) -> t.Array[numpy.str_]:
+    def decode_to_str(self) -> t.Array[t.DTypeStr]:
         """Return the array of string identifiers corresponding to self.
 
         For instance:
diff --git a/openfisca_core/indexed_enums/types.py b/openfisca_core/indexed_enums/types.py
index ac47be816..34bc43af3 100644
--- a/openfisca_core/indexed_enums/types.py
+++ b/openfisca_core/indexed_enums/types.py
@@ -1,16 +1,25 @@
-from openfisca_core.types import Array
+from openfisca_core.types import (
+    Array,
+    DTypeBool,
+    DTypeEnum,
+    DTypeInt,
+    DTypeObject,
+    DTypeStr,
+    Enum,
+)
 
 import abc
-import enum
 
-import numpy
 
+class EnumArray(Array[DTypeEnum], metaclass=abc.ABCMeta): ...
 
-class Enum(enum.Enum):
-    index: int
 
-
-class EnumArray(Array[numpy.int16], metaclass=abc.ABCMeta): ...
-
-
-__all__ = ["Array", "Enum", "EnumArray"]
+__all__ = [
+    "Array",
+    "DTypeBool",
+    "DTypeEnum",
+    "DTypeInt",
+    "DTypeObject",
+    "DTypeStr",
+    "Enum",
+]
diff --git a/openfisca_core/periods/types.py b/openfisca_core/periods/types.py
index 092509c62..952c2b280 100644
--- a/openfisca_core/periods/types.py
+++ b/openfisca_core/periods/types.py
@@ -173,11 +173,6 @@ class PeriodStr(str, metaclass=_PeriodStrMeta):  # type: ignore[misc]
 
 __all__ = [
     "DateUnit",
-    "ISOCalendarStr",
-    "ISOFormatStr",
     "Instant",
-    "InstantStr",
     "Period",
-    "PeriodStr",
-    "SeqInt",
 ]
diff --git a/openfisca_core/types.py b/openfisca_core/types.py
index 711e6c512..0518887f8 100644
--- a/openfisca_core/types.py
+++ b/openfisca_core/types.py
@@ -1,13 +1,17 @@
 from __future__ import annotations
 
 from collections.abc import Iterable, Sequence, Sized
-from numpy.typing import NDArray
+from numpy.typing import DTypeLike, NDArray
 from typing import Any, NewType, TypeVar, Union
 from typing_extensions import Protocol, TypeAlias
 
+import enum
+
 import numpy
 import pendulum
 
+# Config
+
 _N_co = TypeVar("_N_co", bound=numpy.generic, covariant=True)
 
 #: Type representing an numpy array.
@@ -21,6 +25,26 @@
 #: Generic type vars.
 _T_co = TypeVar("_T_co", covariant=True)
 
+#: Type for bool arrays.
+DTypeBool: TypeAlias = numpy.bool_
+
+#: Type for int arrays.
+DTypeInt: TypeAlias = numpy.int32
+
+#: Type for float arrays.
+DTypeFloat: TypeAlias = numpy.float32
+
+#: Type for string arrays.
+DTypeStr: TypeAlias = numpy.str_
+
+#: Type for Enum arrays.
+DTypeEnum: TypeAlias = numpy.int16
+
+#: Type for date arrays.
+DTypeDate: TypeAlias = numpy.datetime64
+
+#: Type for "any" arrays.
+DTypeObject: TypeAlias = numpy.object_
 
 # Entities
 
@@ -80,6 +104,13 @@ def clone(self, population: Any, /) -> Holder: ...
     def get_memory_usage(self, /) -> Any: ...
 
 
+# Indexed enums
+
+
+class Enum(enum.Enum):
+    index: int
+
+
 # Parameters
 
 
@@ -189,3 +220,6 @@ def __call__(
 
 class Params(Protocol):
     def __call__(self, instant: Instant, /) -> ParameterNodeAtInstant: ...
+
+
+__all__ = ["DTypeLike"]
diff --git a/openfisca_core/variables/__init__.py b/openfisca_core/variables/__init__.py
index 1ab191c5c..31a436b09 100644
--- a/openfisca_core/variables/__init__.py
+++ b/openfisca_core/variables/__init__.py
@@ -21,6 +21,6 @@
 #
 # See: https://www.python.org/dev/peps/pep-0008/#imports
 
-from .config import FORMULA_NAME_PREFIX, VALUE_TYPES  # noqa: F401
+from .config import FORMULA_NAME_PREFIX  # noqa: F401
 from .helpers import get_annualized_variable, get_neutralized_variable  # noqa: F401
 from .variable import Variable  # noqa: F401
diff --git a/openfisca_core/variables/config.py b/openfisca_core/variables/config.py
index 54270145b..043665e32 100644
--- a/openfisca_core/variables/config.py
+++ b/openfisca_core/variables/config.py
@@ -1,53 +1 @@
-import datetime
-
-import numpy
-
-from openfisca_core import indexed_enums
-from openfisca_core.indexed_enums import Enum
-
-VALUE_TYPES = {
-    bool: {
-        "dtype": numpy.bool_,
-        "default": False,
-        "json_type": "boolean",
-        "formatted_value_type": "Boolean",
-        "is_period_size_independent": True,
-    },
-    int: {
-        "dtype": numpy.int32,
-        "default": 0,
-        "json_type": "integer",
-        "formatted_value_type": "Int",
-        "is_period_size_independent": False,
-    },
-    float: {
-        "dtype": numpy.float32,
-        "default": 0,
-        "json_type": "number",
-        "formatted_value_type": "Float",
-        "is_period_size_independent": False,
-    },
-    str: {
-        "dtype": object,
-        "default": "",
-        "json_type": "string",
-        "formatted_value_type": "String",
-        "is_period_size_independent": True,
-    },
-    Enum: {
-        "dtype": indexed_enums.ENUM_ARRAY_DTYPE,
-        "json_type": "string",
-        "formatted_value_type": "String",
-        "is_period_size_independent": True,
-    },
-    datetime.date: {
-        "dtype": "datetime64[D]",
-        "default": datetime.date.fromtimestamp(0),  # 0 == 1970-01-01
-        "json_type": "string",
-        "formatted_value_type": "Date",
-        "is_period_size_independent": True,
-    },
-}
-
-
 FORMULA_NAME_PREFIX = "formula"
diff --git a/openfisca_core/variables/variable.py b/openfisca_core/variables/variable.py
index 926e4c59c..f409a7524 100644
--- a/openfisca_core/variables/variable.py
+++ b/openfisca_core/variables/variable.py
@@ -9,12 +9,13 @@
 import numpy
 import sortedcontainers
 
-from openfisca_core import commons, periods, types as t
+from openfisca_core import commons, config, periods, types as t
 from openfisca_core.entities import Entity, GroupEntity
 from openfisca_core.indexed_enums import Enum, EnumArray
 from openfisca_core.periods import DateUnit, Period
 
-from . import config, helpers
+from . import helpers
+from .config import FORMULA_NAME_PREFIX
 
 
 class Variable:
@@ -111,10 +112,10 @@ def __init__(self, baseline_variable=None) -> None:
             attr,
             "value_type",
             required=True,
-            allowed_values=config.VALUE_TYPES.keys(),
+            allowed_values=config.value_types.keys(),
         )
-        self.dtype = config.VALUE_TYPES[self.value_type]["dtype"]
-        self.json_type = config.VALUE_TYPES[self.value_type]["json_type"]
+        self.dtype = config.value_types[self.value_type].dtype
+        self.json_type = config.value_types[self.value_type].json_type
         if self.value_type == Enum:
             self.possible_values = self.set(
                 attr,
@@ -138,7 +139,7 @@ def __init__(self, baseline_variable=None) -> None:
                 attr,
                 "default_value",
                 allowed_type=self.value_type,
-                default=config.VALUE_TYPES[self.value_type].get("default"),
+                default=config.value_types[self.value_type].default,
             )
         self.entity = self.set(attr, "entity", required=True, setter=self.set_entity)
         self.definition_period = self.set(
@@ -166,7 +167,7 @@ def __init__(self, baseline_variable=None) -> None:
             attr,
             "is_period_size_independent",
             allowed_type=bool,
-            default=config.VALUE_TYPES[self.value_type]["is_period_size_independent"],
+            default=config.value_types[self.value_type].is_period_size_independent,
         )
 
         self.introspection_data = self.set(
@@ -176,7 +177,7 @@ def __init__(self, baseline_variable=None) -> None:
 
         formulas_attr, unexpected_attrs = helpers._partition(
             attr,
-            lambda name, value: name.startswith(config.FORMULA_NAME_PREFIX),
+            lambda name, value: name.startswith(FORMULA_NAME_PREFIX),
         )
         self.formulas = self.set_formulas(formulas_attr)
 
@@ -351,7 +352,7 @@ def raise_error() -> NoReturn:
                 msg,
             )
 
-        if attribute_name == config.FORMULA_NAME_PREFIX:
+        if attribute_name == FORMULA_NAME_PREFIX:
             return datetime.date.min
 
         FORMULA_REGEX = r"formula_(\d{4})(?:_(\d{2}))?(?:_(\d{2}))?$"  # YYYY or YYYY_MM or YYYY_MM_DD
diff --git a/openfisca_tasks/lint.mk b/openfisca_tasks/lint.mk
index 656e44a11..6b5511c9b 100644
--- a/openfisca_tasks/lint.mk
+++ b/openfisca_tasks/lint.mk
@@ -43,6 +43,7 @@ check-types:
 		openfisca_core/entities \
 		openfisca_core/indexed_enums \
 		openfisca_core/periods \
+		openfisca_core/config.py \
 		openfisca_core/types.py
 	@$(call print_pass,$@:)
 
diff --git a/openfisca_web_api/loader/variables.py b/openfisca_web_api/loader/variables.py
index 6730dc081..a516df5e7 100644
--- a/openfisca_web_api/loader/variables.py
+++ b/openfisca_web_api/loader/variables.py
@@ -2,8 +2,8 @@
 import inspect
 import textwrap
 
+from openfisca_core import config
 from openfisca_core.indexed_enums import Enum
-from openfisca_core.variables import VALUE_TYPES
 
 
 def get_next_day(date):
@@ -76,7 +76,7 @@ def build_variable(variable, country_package_metadata):
     result = {
         "id": variable.name,
         "description": variable.label,
-        "valueType": VALUE_TYPES[variable.value_type]["formatted_value_type"],
+        "valueType": config.value_types[variable.value_type].formatted_value_type,
         "defaultValue": get_default_value(variable),
         "definitionPeriod": variable.definition_period.upper(),
         "entity": variable.entity.key,