diff --git a/changelog_entry.yaml b/changelog_entry.yaml
index e69de29b..7db28cb8 100644
--- a/changelog_entry.yaml
+++ b/changelog_entry.yaml
@@ -0,0 +1,7 @@
+- bump: minor
+  changes:
+    added:
+    - Support for adds/subtracts targeting parameters.
+    - Support for adds/subtracts targeting year ranges where no parameters exist.
+    changed:
+    - Deprecated sum_of_variables.
\ No newline at end of file
diff --git a/policyengine_core/commons/formulas.py b/policyengine_core/commons/formulas.py
index 9e390809..df9ceb36 100644
--- a/policyengine_core/commons/formulas.py
+++ b/policyengine_core/commons/formulas.py
@@ -10,6 +10,8 @@
 from numpy import round as round_
 from numpy import select, where
 
+from warnings import warn
+
 from policyengine_core.parameters.parameter_node import ParameterNode
 from policyengine_core.periods.period_ import Period
 from policyengine_core.populations.population import Population
@@ -395,6 +397,10 @@ def sum_of_variables(variables: Union[List[str], str]) -> Callable:
         Callable: A function that sums the values of the variables.
     """
 
+    warn(
+        f"Sum-of-variables formulas are deprecated- please use `adds` or `subtracts` instead."
+    )
+
     def sum_of_variables(entity, period, parameters):
         if isinstance(variables, str):
             # A string parameter name is passed
diff --git a/policyengine_core/scripts/run_data.py b/policyengine_core/scripts/run_data.py
index b608d928..53c46537 100644
--- a/policyengine_core/scripts/run_data.py
+++ b/policyengine_core/scripts/run_data.py
@@ -9,11 +9,10 @@
 
 
 def dataset_summary(datasets: List[Dataset]) -> str:
-    years = list(sorted(list(set(sum([ds.years for ds in datasets], [])))))
     df = pd.DataFrame(
         {
-            year: ["✓" if year in ds.years else "" for ds in datasets]
-            for year in years
+            "Label": [ds.label for ds in datasets],
+            "Stored": ["✓" if ds.exists else "" for ds in datasets],
         },
         index=[ds.name for ds in datasets],
     )
diff --git a/policyengine_core/simulations/simulation.py b/policyengine_core/simulations/simulation.py
index d0cd74ab..240a2b82 100644
--- a/policyengine_core/simulations/simulation.py
+++ b/policyengine_core/simulations/simulation.py
@@ -699,7 +699,7 @@ def _run_formula(
         formula = variable.get_formula(period)
         if formula is None:
             values = None
-            if variable.adds is not None:
+            if variable.adds is not None and len(variable.adds) > 0:
                 if isinstance(variable.adds, str):
                     try:
                         adds_parameter = get_parameter(
@@ -715,10 +715,20 @@ def _run_formula(
                     adds_list = variable.adds
                 values = 0
                 for added_variable in adds_list:
-                    values = values + self.calculate(
-                        added_variable, period, map_to=variable.entity.key
-                    )
-            if variable.subtracts is not None:
+                    if added_variable in self.tax_benefit_system.variables:
+                        values = values + self.calculate(
+                            added_variable, period, map_to=variable.entity.key
+                        )
+                    else:
+                        try:
+                            parameter = get_parameter(
+                                self.tax_benefit_system.parameters,
+                                added_variable,
+                            )
+                            values = values + parameter(period.start)
+                        except:
+                            pass
+            if variable.subtracts is not None and len(variable.subtracts) > 0:
                 if isinstance(variable.subtracts, str):
                     try:
                         subtracts_parameter = get_parameter(
@@ -735,9 +745,24 @@ def _run_formula(
                 if values is None:
                     values = 0
                 for subtracted_variable in subtracts_list:
-                    values = values - self.calculate(
-                        subtracted_variable, period, map_to=variable.entity.key
-                    )
+                    if (
+                        subtracted_variable
+                        in self.tax_benefit_system.variables
+                    ):
+                        values = values - self.calculate(
+                            subtracted_variable,
+                            period,
+                            map_to=variable.entity.key,
+                        )
+                    else:
+                        try:
+                            parameter = get_parameter(
+                                self.tax_benefit_system.parameters,
+                                subtracted_variable,
+                            )
+                            values = values + parameter(period.start)
+                        except:
+                            pass
             return values
 
         if self.trace and not isinstance(