With buildings providing global happiness, it's pretty easy to shell out for happiness unless you're going full on Manifest Destiny mode.
Civ5 uses 2 kinds of Growth-Limiters :
Empire-Growth-Limiter (Global Un/Happiness) and
City-Growth-Limiter (Local Un/Happiness).
Local happiness allows to grow bigger cities while global happiness allows to have more cities or grow even bigger cities. This is a valid concept. The big design mistake is to call both types simply
Un/Happiness in most of the in-game descriptions for buildings, National Wonders, Wonders, Social Policies, Religious Traits, etc. It would have been better to use a name like "Empire Stability Points" instead of global happiness to avoid the confusion.
Buildings can have the following happiness-attributes :
Happiness (= local happiness, e.g. CIRCUS, COLOSSEUM),
UnmoddedHappiness (= global happiness, e.g. NOTRE_DAME)
UnhappinessModifier (FORBIDDEN_PALACE)
HappinessPerCity (CN_TOWER),
HappinessPerXPolicies (PRORA_RESORT),
CityCountUnhappinessMod (??? unused),
NoOccupiedUnhappiness (COURTHOUSE)
Building_BuildingClassHappiness (NEUSCHWANSTEIN - CASTLE)
Social Policies can have the following happiness-attributes :
ExtraHappiness
ExtraHappinessPerCity
UnhappinessMod (MERITOCRACY)
CityCountUnhappinessMod
OccupiedPopulationUnhappinessMod
CapitalUnhappinessMod (MONARCHY)
HappinessPerGarrisonedUnit (MILITARY_CASTE)
HappinessPerTradeRoute (MERITOCRACY)
HappinessPerXPopulation (ARISTOCRACY)
ExtraHappinessPerLuxury (PROTECTIONISM)
UnhappinessFromUnitsMod
HappinessToCulture (FINE_ARTS)
HappinessToScience (RATIONALISM)
HalfSpecialistUnhappiness (UNIVERSAL_SUFFRAGE)
Policy_BuildingClassHappiness (e.g. NAVAL_TRADITION - HARBOR)
How can the player know which of these attributes provide local or global happiness if they are simply called Un/Happiness in most descriptions? And if the player does not know this, how can the player develop a strategy to counter happiness-problems which automatically arise when going to war, conquering cities, expanding the empire? The player is forced to simply react to happiness-issues and to trial-and-error/experience ...
(Note : Tall-Players who choose the simple path of a 3-4 cities Tradition game without conquering cities usually do not need to differentiate between local and global happiness since their tiny empire causes only a small amount of global unhappiness and all the global excess-happiness is used to allow bigger cities, generate golden ages and culture. Lack of Global Happiness is a problem experienced more in wide and ultra-wide empires.)