The specific statutory duties for assessors can be found in the New York City Charter. This document serves as the fundamental legal framework for the governance of New York City, outlining the roles, responsibilities, and procedures specific to various city agencies, including the Department of Finance, which oversees property assessment. The City Charter delineates the duties of assessors, such as evaluating property values and establishing the assessment roll, thereby ensuring that property taxes are assessed fairly and consistently. In contrast, the New York State Constitution provides broader principles and frameworks for governance in the entire state but does not specify duties related to individual assessors. Local government regulations may have relevant information, but they generally pertain to local ordinances rather than the mandated duties established at the city level. Federal tax laws focus on taxation at the federal level and do not address the specific responsibilities of local assessors. Thus, the City Charter is the most direct and authoritative source for assessors' statutory duties within New York City.

In real estate, the cost of improvements being equal to the value of a property typically occurs when those improvements are new. This is because new improvements reflect the most current construction practices, materials, and technologies, which add significant value to the property. The initial cost of these improvements usually represents their highest potential value, as they have not yet depreciated or lost value over time. New properties or newly renovated spaces tend to capture the market's willingness to pay based on the quality and novelty of the improvements. While other scenarios can affect the relationship between cost and value, such as selling the property or renting it out, they do not guarantee that the cost will equal the value. Market conditions also play a crucial role; for example, even in optimal conditions, various external factors may influence the actual market value, leading to discrepancies between what was spent on the property and its perceived worth in the market.

Excess rent signifies the situation in which the contract rent paid by a tenant is greater than the economic rent, which is the market value or fair rental value of a property given its location, condition, and other factors. This concept often arises in real estate when analyzing leases and determining whether they are more favorable or disadvantageous compared to prevailing market rates. This distinction is crucial for property valuation and assessments because understanding excess rent helps assessors measure the financial performance of a property. When contract rent exceeds economic rent, it can indicate that a property is rented at a premium, possibly due to factors such as high demand, location desirability, or unique property characteristics. The other options discuss related concepts but do not accurately describe what excess rent specifically means. For instance, while the difference between actual and expected rents is about rent performance, it does not focus on the comparative analysis central to excess rent. Similarly, lease payments being less than market rates and increases in rent following property improvements relate more to market dynamics but do not encapsulate the essence of excess rent.

The EAT formula stands for "Effective Tax Rate," which is calculated by multiplying the assessment ratio by the tax rate. This formula is essential in real estate and property taxation as it helps property owners understand how much they will be paying in taxes based on their property's assessed value and the local tax rate set by the government. The assessment ratio reflects the proportion of a property’s market value that is subject to taxation. The tax rate, determined by local municipalities, indicates the amount of tax payable per unit of assessed property value. By using the EAT formula, one can accurately estimate the effective tax burden on a property, which is particularly useful for budgeting and financial planning. Understanding the EAT formula is critical for anyone involved in real estate or property management in New York City, where property taxes significantly impact overall operating costs and investment returns. The other choices, while they might seem relevant in certain contexts, do not correctly represent the meaning of the EAT formula in terms of property taxation.