Spirit is a statistic provided by Decor. It benefits your town by providing discounts on expansion prices, as well as reducing wait time for new clones and construction projects.
Since update 1.3 and beyond Spirit scales with the level of the player. The wait times and construction times scale equally with the cost reduction benefit of the Spirit level.
1 level of Spirit equals 1 percent reduction on waiting times, contruction times and the cost of expansion and max out at 50 percent. The Spirit needed for these maximum reductions is dictated by the level of the player.
As the level of the player increases, by land expansion, the Spirit needed for maximum reduction also increases. This way players will continually need to add decors as they level up if they want the maximum reduction on expansion costs, wait times and contruction times.
To help keep track of your spirit compared to available land space a Spirit Counter can be displayed above the Land Watch from the toggle button in the Funeral Parlor.