- quantitative analysis is often used in the beginning stages of plan making
- Either Interval Scale or Ratio Scale
Interval Scale – values that have an ordered relationship with magnitude. (e.g. 80 deg.F Is not 2x 40 deg.)
Ratio Scale – values that are in an ordered relationship with equal intervals. (e.g. 10ml is 2x more than 5ml)
- Quantitative Data can be Continuous or Discrete
Continuous Variables can Continuously change (age or Time)
Discrete Variables are selected from a given set (number of children in a class, or number players)
- Normal data or Ordinal Data
Normal Data – Lacks any intrinsic order and classified into mutually exclusive groups
- Race, social Security Number and Sex
Ordinal Data – Ranked so that the difference between them can be ranked so that magnitude between them can be determined
- Used to measure or represent data in a dataset, Mean, Median or Mode
Mean – average in a distribution (sum / total)
Median – the middle number in a ranked dataset
Mode – most frequent value in a dataset
Population: the total number of some entity or group
Sample: a subset of a given population
Descriptive Statistics: summarize a population or a sample of the population using characteristics of the group.
Inferential Statistics: are used to describe and make inferences about a population based on observations made from a sample.
Measures of Dispersion: values used to represent the extent to which data differs from each other. And include
- Range: The Difference between highest and lowest value
- Variance: Measures how far numbers are from the mean
- Standard Deviation: The square root of the Variance
- Coefficient of Variation: calculated by dividing the Standard Deviation by the Mean of a dataset
- Standard Error: represents the standard deviation of a sampling distribution. This measure indicates the degree of fluctuation while sampling
- Confidence Interval: represents a range of values within a dataset which is likely to include an unknown population parameter. (e.g. a political poll may say that 60 percent of the population, +/- 5)
Random: where everyone in a population has an equal chance of being selected.
System: a sample for which a list of a given population is created and every nth person is selected.
Stratified: a sample that is selected from a population that is divided into multiple groups or classes.
Cluster: a given population is separated into logical sections and then a sample is selected from the sections.
Convenience: this is a sample that uses the individuals that are most readily available.
Volunteer: a sample for which people volunteer their participation.
Normal Distribution – Bell Curve - data is one that is symmetrical around a dataset’s mean
Hypothesis Testing – Method to test an assumption – assess whether the results happened by chance or if there is a correlation
- Null Hypothesis – statement use that claims that there is no correlation between variables involved.
Chi Square – statistical test that measures the amount of difference between two distributions. Commonly used in inferential statistics
Z-score - is a numerical measurement of a value’s relationship to the mean of a dataset. Measured in standard deviation units, this test determines the likelihood, or probability that something would happen.
- T-test - is a method used in inferential statistics to determine if there is a significant difference between the means of two datasets.
Correlation Test - are statistical tests that measure the relationship strength between variables.
- Correlation Coefficient: resulting from the test, indicates the type and strength of the relationship between the variables. A correlation coefficient can range from 1 to -1 and where the value falls on this scale indicates the strength between the variables. A correlation coefficient closer to 1 indicates a strong variable relationship
Regression - measure of the effect that independent variables have on a specific dependent variable. For example, a regression analysis could explore the relationship between hours of sleep prior to taking a test and the subsequent score of the test to determine the effect that hours of sleep has on test scores.
Sampling Error - occurs when a sample taken from a larger population is not truly representative of that population as a whole.
- There are four major population estimate methods: Linear, systematic, step down Ration, Cohort Survival
1. Linear: assume that the rate of historical population change will continue to be the rate at which it changes in the future
2. Symptomatic: involves using readily available data to estimate current population (eg new building permits for homes with the Census average household size)
3. Step-Down Ration: uses the ratio between a city’s population and that for a larger area such as the county to estimate
4. Cohort Survival - uses data such as the birth rate, death rate, and migration rate for a given area and combines it with the existing population to estimate the future population for different age cohorts. Specific age groups are cohorts. This is most accurate method of estimating population. The following terms include the data that is used to complete the cohort survival method:
- Net Migration
- Birthrate and Deathrate
· General Fertility Rate is the babies born per 1000 females of child bearing age
· Death rate per 1000 people
- Natural Increase – difference between babies born and people who died.
- Exponential Projection Method: Previous growth rates to determine future population
· Modified Exponential Projection assumes growth rate will decrease with time.
· Gompertz Projection Method assumes growth rate will increase with time.
- Distribution Housing Unit Method – used in areas with slow growth. Housing unit data and multiplies by occupancy rate from the Census
- A method for dividing the economic activity in a region into two categories: Basic and Non-Basic Activities.
Basic Economic Activities are those that are exported from a region to bring wealth in from outside the region
Non-Basic Economic Activities: are sources of support for a Basic Economic Activities and are locally oriented.
- Basic and Non-Basic are calculated using a Location Quotient.
Location Quotient: is calculated for each industry by “(local employment in an industry/total local employment) Divided By (Nation employment in an industry/total national employment)” When an industry has a location quotient greater than 1 it is considered a BASE Industry for the region.
Shift-Share Analysis: comparative method that examines change in economic variables for two points in time. Changes are calculated at a national and regional level. Broken into three components
- National Growth effect: portion of the reginal change that is attributed to the national growth in that industry
- Industry Mix: Portion of regional change in an industry that is attributed to the growth of that industry
- Local Share; portion of the change attributed to other regional influences.
Input – Output Analysis – Can be used to determine economic impact that a specific project can have on a region.
NAICS North American Industry Classification System – applies a 6 digit code to businesses based on type of industry, helps planners.
- 2010 Census used long form and short form
- 2020 Census just used Short form (10 questions)
American Community Survey – replaced long form, done yearly to 2.5% of the population.
Census Block - is an area of 400 housing units (Smallest unit)
Census Block Group - is a group of census blocks
Census Tract- is smallest geographic area that data is collected. (between 2000 and 8000 people)
Urbanized Area – 50,000 people, Density of 1,000 people per sq mile
Urban Cluster – between 2,500 and 50,000, Density still at 1,000 per square mile
Metropolitan Statistical Area (MSA) – 100,000 people and has at least on city of 50,000 in the area
Micropolitan Statistical Area – between 10,000 and 50,000 people
Consolidated MSA (CMSA)- has at least 2 MSA and more that 1,000,000 people
Census Designated Place (CDP)- is a city.
Mega City – more than 10M people
Threshold Population – the min people required for a particular service to be provided in that area.
Population Trend
- 1900 – 40% of people lived in urban areas
- 1960 – 70%
- 1970 – 74%
- 2010 – 81%
Population Growth
- 1900 – 76M
- 2010 – 308M
Baby Boomers – 1946 thru 1964
Gen X – 1965 thru 1976
Gen Y – 1977 thru 2000
Gen Z – 2000 -
- Map Projection methods are, Conic, Cylindrical, and Planar
- “Ladder of Citizen Participation” developed by Sherry Arnstein – defines levels of citizen involvement based on the form of participation utilized. Eight rungs of the ladder are separated not three different power levels: Citizen Power, Tokenism, and Non-participation.
Focus Groups – fast compared to larger community effort. Small groups,
Design Charette – collaborative effort, typically detailed design or plan, build consensus, last on to three days
Delphi Method – developed by US military 1944, create consensus between two or more conflicting groups, complete a series of questions, hypothesis about given topic, answers are presented anonymously, the responses are presented to entire participating group in successive rounds of arguments and counter arguments until it is narrowed down and consensus is reached.
Force Field Analysis – simple brainstorming, presents alternatives and let stakeholders determine what they like or don’t like about each one. With a list of likes and dislikes the group can prioritize the dislikes and overcome the ones of high priority.
Nominal Group Technique – brainstorming, any size group. Process works by presenting a problem to a group and then member of the group makes suggested solutions. With all the suggestions list the group can rank, prioritize and select a solution.
Fractional – a neutral parky helps conflicting groups come to a consensus. A professional facilitator
Mediation: Mediation process, neutral third party leads discussion. Mediator is tasked with identifying priorities.
Visual Preference Survey – Visual aids for citizens to evaluate design alternatives.
Visioning – Citizens develop an idea of what they want the community to be in the future, rather than focus on current conditions. Occurs early in the planning process, and used for long term planning.
- All people should have access to public process.
- A tool used to measure the revenue and costs to be incurred by a local entity. E.g. A new residential development will required addition services such as utilities, emergency services, transit services, etc. These additional services are calculated as a cost to the town. The revenue from the new development is calculated from property tax. Fiscal impact analysis fails to capture qualitative benefits. To account for the flaws in basic fiscal impact analysis calculations, several methods for conducting the analysis that better represent the full impact are:
Disaggregated Per Capital Method -this method separates proposed developments by their uses and determines a different cost for each. For example, the cost to a city for providing services to a new residential development or to a large manufacturing plant will be different.
Average Per Capita Method - considered the simplest method for conducting fiscal impact analyses, it is also the most unreliable as it assumes that the cost to provide services to a new development will be equal to the cost of providing service to the existing population. To perform this method, one would first divide the total budget of the jurisdiction by the population to produce an average per capita cost. Then this figure is multiplied by the projected population resulting from the new development to determine the new total cost for the jurisdiction.
Adjusted Per Capita Method - largely calculated in the same way as the previous method, costs are adjusted based on the expectations of the proposed development.
Dynamic Method - the most complex of the methods outlined here, this method is more reliable than others but also requires more data and time to complete. It uses local time-series data to determine the revenue generated by previously implemented developments through taxes and then applies this revenue generation rate to the proposed development based on its specific use and size
Capital Improvement Planning or Programming -is a type of planning that primarily works to link comprehensive or strategic plans for local municipalities or entities to an annual budget.
Cost-benefit analysis - is a tool typically used by planners working on public projects to estimate the monetary value of the benefits and costs of a project. This method assists planners in selecting which projects provide the most benefit to the community in which they will be implemented. The larger the ratio of benefits to cost is, the greater total benefit a project will provide to a community. Adding to the difficulty of the cost-benefit analysis method, to successfully complete one it is necessary to convert all costs and benefits to a monetary value, even those that may be qualitative such as the preservation of open space. Cost-Benefit Analysis is commonly used, there are other methods:
Planning Balance Sheets
- this method involves creating an evaluation matrix where project alternatives (rows in the matrix) are compared against one another using identified evaluation criteria (columns in the matrix). This alternative evaluation method simplifies the comparison of projects based on environmental or social criteria that may be hard to quantify, and thus include in a cost-benefit analysis.
Goals Achievement Matrix
- similar to a planning balance sheet, this evaluation method evaluates the costs and benefits of a group of projects or alternatives in relation to identified project goals and the desired goals of community groups that may be impacted by the projects being evaluated. For this method, the identified goals and group interests are weighted to reflect their importance to the impacted communities. The result is a measure of performance of each project alternative in relation to the identified goals.
Annualized cost of a project and the total cost of a project over its lifetime
- these two cost metrics are most commonly used to compare two or more projects that are determined to produce the same benefits to a community. The cost metrics allow for further evaluation and timing of the project costs to allow for a more informed selection of a project from a group of projects that provide identical benefits.
Cost-effectiveness analysis - is a method for determining the effectiveness of different project alternatives or strategies when a jurisdiction has a limited budget. This analysis helps in deciding between competing project alternatives based on which will provide the greatest return. While candidates will not be asked to complete a cost-effective analysis on the exam it is still good practice to understand the formula used to calculate it: CE Ratio = (cost of new project - cost of current conditions)/(effect of new project – effect of current conditions)
Net Present Value - This is a method for determining the monetary value of a project, discounted to today’s dollars. The variables needed to complete this calculation are the project’s life span in years, the quantified monetary benefits, the quantified monetary cost of the project, and the interest rate.
- Budgets are generally Capital and Operating. (capital budget is legally adopted and a CIP is not legally binding)
- It is important for planners, and candidates taking the exam, to understand the appropriate type of budgeting to use when presented with different scenarios. Primarily, there are four general types of budgets that are at the disposal of government agencies:
1. Line-Item budget – Most Simple method of budgeting. Expenses are separated into groups with emphasis on project expenditures for the next year. Disadvantage as its short term and lack of any major plan like a CIP or comprehensive plan.
o Performances Based Budget – Tying funding for projects to performance or evaluation measures. E.g. Improved performance of a program or activity will increase funding, especially if goals are met. Incentivises performance. Require a lot of data. The Practice of Local Government referred to as the “Green Bible” identifies three types of performance-based budgeting are identified: Planning Programing Budgetary System (PPBS), Zero-Based Budgeting (ZBB), and the Dayton System.
2. (PPBS) Planning, Programming, Budgeting Systems – like standard performance-based budgeting but allows for an evaluation of a programs performance in achieving departmental goals. Not common as requires significant data
3. Zero Base Budgeting – requires justification of all expenses for a reporting period. Essentially starting from zero eath time budget is prepared. Evaluated programs performance to receive low, medium or high funding
4. The Dayton System – combination of PPBS and ZBB, and is more commonly used, especially by big cities. Involves listing cities programs as rows and columns that identify program characteristics such as: previous year funding, staff time, proposed funding for current reporting period.
Current Revenue – money raised by tax’s
Reserve Funds – Funds saved for the purpose of capital projects and can not be used for emergency purposes.
Pay as you Go – Finance capital projects with use of current funds.
General Obligation Bonds – Tax revenue to pay back voter approved bonds for major capital projects.
Revenue Bonds – used for projects that crate Revenue, paid back by the money generated from the new service or project. Do not need voter approval.
Tax Increment Funding – Tax increase of finished project pays back the bond. Used in areas with significant blight.
Progressive -Tax rate increases as income increases. Citizens that make more money area assessed a high tax
Proportional - Assessed tax rate does not change with income. Property tax is a proportional tax as the same rate is applied to everyone
Regressive - Opposite from progressive – Tax Rate decreases as income rises.